diff --git a/btrbk b/btrbk
index 87e9195..2e46fd0 100755
--- a/btrbk
+++ b/btrbk
@@ -1378,31 +1378,26 @@ sub btrfs_send_receive($$;$$$)
   my $snapshot = shift || die;
   my $target = shift || die;
   my $parent = shift;
-  my $clone_src = shift // [];  # arrayref of [ vinfo, correlated_target_node ]
+  my $clone_src = shift // [];
   my $ret_vol_received = shift;
   my $snapshot_path = $snapshot->{PATH} // die;
   my $target_path = $target->{PATH} // die;
   my $parent_path = $parent ? $parent->{PATH} : undef;
-  my @clone_src_path;
-  my $incremental_clones = config_key($target, "incremental_clones");
-  if(my $cnt = $incremental_clones) {
-    @clone_src_path = map { --$cnt < 0 ? ( ) : $_->[0]{PATH} } @$clone_src;
-  }
 
   my $vol_received = vinfo_child($target, $snapshot->{NAME});
   $$ret_vol_received = $vol_received if(ref $ret_vol_received);
 
   print STDOUT "Creating backup: $vol_received->{PRINT}\n" if($show_progress && (not $dryrun));
 
+  INFO "[send/receive] target: $vol_received->{PRINT}";
   INFO "[send/receive] source: $snapshot->{PRINT}";
   INFO "[send/receive] parent: $parent->{PRINT}" if($parent);
-  INFO "[send/receive] target: $vol_received->{PRINT}";
-  INFO "[send/receive] using " . (scalar @clone_src_path) . " clone sources" if($incremental_clones);
+  INFO "[send/receive] clone-src: $_->{PRINT}" foreach(@$clone_src);
 
   my @send_options;
   my @receive_options;
   push(@send_options, '-p', { unsafe => $parent_path} ) if($parent_path);
-  push(@send_options, '-c', { unsafe => $_ } ) foreach(@clone_src_path);
+  push(@send_options, '-c', { unsafe => $_ } ) foreach(map { $_->{PATH} } @$clone_src);
   # push(@send_options, '-v') if($loglevel >= 3);
   # push(@receive_options, '-v') if($loglevel >= 3);
 
@@ -2951,7 +2946,6 @@ sub _correlated_nodes($$)
   my $uuid = $src_vol->{node}{uuid};
   my $received_uuid = $src_vol->{node}{received_uuid};
   $received_uuid = undef if($received_uuid eq '-');
-  TRACE "correlated_nodes: src_vol=\"$src_vol->{PRINT}\", droot=\"$droot->{PRINT}\"";
 
   my $received_uuid_hash = $droot->{node}{TREE_ROOT}{RECEIVED_UUID_HASH};
   my $uuid_hash = $droot->{node}{TREE_ROOT}{UUID_HASH};
@@ -2965,7 +2959,7 @@ sub _correlated_nodes($$)
   }
 
   @ret = grep($_->{readonly}, @match);
-  TRACE "correlated_nodes: " . scalar(@ret) . " receive targets in \"$droot->{PRINT}/\" for: $src_vol->{PRINT}";
+  TRACE "correlated_nodes: droot=\"$droot->{PRINT}/\", src_vol=\"$src_vol->{PRINT}\": " . join(", ", map _fs_path($_),@ret) if($loglevel >= 4);
   return @ret;
 }
 
@@ -3005,26 +2999,25 @@ sub get_receive_targets($$;@)
 
 
 # returns best correlated receive target within droot (independent of btrbk name)
-sub get_best_correlated_target($$;@)
+sub get_best_correlated($$;@)
 {
   my $droot = shift || die;
   my $src_vol = shift || die;
   my %opts = @_;
-  my $filtered_nodes = $opts{push_filtered_nodes};
+  my $inaccessible_nodes = $opts{push_inaccessible_nodes};
 
   my @correlated = _correlated_nodes($droot, $src_vol); # all matching src_vol, from droot->TREE_ROOT
   foreach (@correlated) {
-    my $vinfo = vinfo_resolved($_, $droot); # $vinfo is within $resolve_droot
-    return $vinfo if($vinfo);
-    push @$filtered_nodes, $_ if($filtered_nodes);
+    my $vinfo = vinfo_resolved($_, $droot); # $vinfo is within $droot
+    return [ $src_vol, $vinfo ] if($vinfo);
   }
   if($opts{fallback_all_mountpoints}) {
     foreach (@correlated) {
       my $vinfo = vinfo_resolved_all_mountpoints($_, $droot); # $vinfo is within any mountpoint of filesystem at $droot
-      return $vinfo if($vinfo);
-      push @$filtered_nodes, $_ if($filtered_nodes);
+      return [ $src_vol, $vinfo ] if($vinfo);
     }
   }
+  push @$inaccessible_nodes, @correlated if($inaccessible_nodes);
   return undef;
 }
 
@@ -3071,8 +3064,8 @@ sub _push_related_children
 
 
 # returns all related readonly nodes (by parent_uuid relationship),
-# sort by absolute cgen delta, favor older
-sub get_related_subvolume_nodes($)
+# sorted by relation distance.
+sub get_related_readonly_nodes($)
 {
   my $vol = shift // die;
   TRACE "related_nodes: resolving related subvolumes of: $vol->{PATH}";
@@ -3100,21 +3093,22 @@ sub get_related_subvolume_nodes($)
   }
   WARN "Maximum distance reached, related subvolume search aborted" if($distance >= 256);
   TRACE "related_nodes: found total=" . scalar(@related_nodes) . " related readonly subvolumes";
-  my @sorted = sort { (abs($cgen_ref - $a->{cgen}) <=> abs($cgen_ref - $b->{cgen})) ||
-                      ($a->{cgen} <=> $b->{cgen}) } @related_nodes;
-  return \@sorted;
+  return \@related_nodes;
 }
 
 
-# returns ( parent, first_matching_target_node )
+# returns parent, along with clone sources
 sub get_best_parent($$$;@)
 {
   my $svol = shift // die;
   my $snaproot = shift // die;
   my $droot = shift || die;
   my %opts = @_;
-  my $fallback_btrbk_basename = $opts{fallback_btrbk_basename} // 1; # default true, see below
-  my $clone_src = $opts{clone_src};
+  my $ret_clone_src          = $opts{clone_src};
+  my $ret_clone_src_extra    = $opts{clone_src_extra};
+  my $ret_target_parent_node = $opts{target_parent_node};
+
+  TRACE "get_best_parent: resolving best common parent for subvolume: $svol->{PRINT}  (droot=$droot->{PRINT})";
 
   # honor incremental_resolve option
   my $source_incremental_resolve = config_key($svol, "incremental_resolve");
@@ -3131,26 +3125,37 @@ sub get_best_parent($$$;@)
   my $source_fallback_all_mountpoints = ($source_incremental_resolve eq "_all_accessible");
   my $target_fallback_all_mountpoints = ($target_incremental_resolve eq "_all_accessible");
 
-  TRACE "get_best_parent: resolving best common parent for subvolume: $svol->{PATH}  (droot=$droot->{PRINT})";
-  my $all_related_nodes = get_related_subvolume_nodes($svol);
+  my @inaccessible_nodes;
+  my %gbc_opts = ( push_inaccessible_nodes  => \@inaccessible_nodes,
+                   fallback_all_mountpoints => $target_fallback_all_mountpoints,
+                 );
 
-  # filter candidates
-  my @candidate;  # candidates for parent, ordered by "best suited"
-  foreach (@$all_related_nodes) {
+  # resolve correlated subvolumes by parent_uuid relationship
+  my %c_rel_id;   # map id to c_related
+  my @c_related;  # candidates for parent (correlated + related), unsorted
+  foreach (@{get_related_readonly_nodes($svol)}) {
     my $vinfo = vinfo_resolved($_, $resolve_sroot);
     if((not $vinfo) && $source_fallback_all_mountpoints) { # related node is not under $resolve_sroot
       $vinfo = vinfo_resolved_all_mountpoints($_, $svol);
     }
     if($vinfo) {
-      push @candidate, $vinfo;
+      my $correlated = get_best_correlated($droot, $vinfo, %gbc_opts);
+      push @c_related, $correlated if($correlated);
+      $c_rel_id{$_->{id}} = $correlated;
     } else {
       DEBUG "Related subvolume is not accessible within $source_incremental_resolve \"$resolve_sroot->{PRINT}\": " . _fs_path($_);
     }
   }
+  # sort by cgen
+  my $cgen_ref = $svol->{node}{readonly} ? $svol->{node}{cgen} : $svol->{node}{gen};
+  my @c_related_older = sort { ($cgen_ref - $a->[0]{node}{cgen}) <=> ($cgen_ref - $b->[0]{node}{cgen}) }
+                        grep { $_->[0]{node}{cgen} <= $cgen_ref } @c_related;
+  my @c_related_newer = sort { ($a->[0]{node}{cgen} - $cgen_ref) <=> ($b->[0]{node}{cgen} - $cgen_ref) }
+                        grep { $_->[0]{node}{cgen} >  $cgen_ref } @c_related;
 
-  # NOTE: get_related_subvolume_nodes() is very sophisticated and
-  # returns all known relations, there is always a chance that
-  # relations get broken.
+  # NOTE: While get_related_readonly_nodes() returns deep parent_uuid
+  # relations, there is always a chance that these relations get
+  # broken.
   #
   # Consider parent_uuid chain ($svol readonly)
   # B->A, C->B, delete B: C has no relation to A.
@@ -3159,43 +3164,88 @@ sub get_best_parent($$$;@)
   # For snapshots (here: S=$svol readwrite) the scenario is different:
   # A->S, B->S, C->S, delete B: A still has a relation to C.
   #
-  # add subvolumes in same directory matching btrbk file name scheme
-  if($fallback_btrbk_basename && exists($svol->{node}{BTRBK_BASENAME})) {
+  # resolve correlated subvolumes in same directory matching btrbk file name scheme
+  my (@c_snapdir_older, @c_snapdir_newer);
+  if(exists($svol->{node}{BTRBK_BASENAME})) {
     my $snaproot_btrbk_direct_leaf = vinfo_subvol_list($snaproot, readonly => 1, btrbk_direct_leaf => $svol->{node}{BTRBK_BASENAME});
-    my @direct_leaf_older = grep { cmp_date($_->{node}{BTRBK_DATE}, $svol->{node}{BTRBK_DATE}) < 0 } @$snaproot_btrbk_direct_leaf;
-    my @direct_leaf_newer = grep { cmp_date($_->{node}{BTRBK_DATE}, $svol->{node}{BTRBK_DATE}) > 0 } @$snaproot_btrbk_direct_leaf;
-    push @candidate, sort { cmp_date($b->{node}{BTRBK_DATE}, $a->{node}{BTRBK_DATE}) } @direct_leaf_older;
-    push @candidate, sort { cmp_date($a->{node}{BTRBK_DATE}, $b->{node}{BTRBK_DATE}) } @direct_leaf_newer;
-    TRACE "get_best_parent: subvolume has btrbk naming scheme, add " . scalar(@direct_leaf_older) . " older and " . scalar(@direct_leaf_newer) . " newer (by file suffix) candidates with scheme: $snaproot->{PRINT}/$svol->{node}{BTRBK_BASENAME}.*";
+    my @sbdl_older = sort { cmp_date($b->{node}{BTRBK_DATE}, $a->{node}{BTRBK_DATE}) }
+                     grep { cmp_date($_->{node}{BTRBK_DATE}, $svol->{node}{BTRBK_DATE}) < 0 } @$snaproot_btrbk_direct_leaf;
+    my @sbdl_newer = sort { cmp_date($a->{node}{BTRBK_DATE}, $b->{node}{BTRBK_DATE}) }
+                     grep { cmp_date($_->{node}{BTRBK_DATE}, $svol->{node}{BTRBK_DATE}) > 0 } @$snaproot_btrbk_direct_leaf;
+
+    @c_snapdir_older = map { $c_rel_id{$_->{node}{id}} // get_best_correlated($droot, $_, %gbc_opts) // () } @sbdl_older;
+    @c_snapdir_newer = map { $c_rel_id{$_->{node}{id}} // get_best_correlated($droot, $_, %gbc_opts) // () } @sbdl_newer;
   }
 
-  # get correlated receive targets of candidates, return first matching within $resolve_droot
-  my @resolved;
-  my @filtered_nodes;
-  my %uniq;
-  foreach my $cand (@candidate) {
-    next if($uniq{$cand->{node}{id}});
-    my $correlated_target = get_best_correlated_target($resolve_droot, $cand, push_filtered_nodes => \@filtered_nodes, fallback_all_mountpoints => $target_fallback_all_mountpoints);
-    if($correlated_target) {
-      TRACE "get_best_parent: common related from root=\"$resolve_droot->{PRINT}\": \"$cand->{PRINT}\", \"$correlated_target->{PRINT}\"";
-      push @resolved, [ $cand, $correlated_target ];
-      last unless($clone_src);
+  if($loglevel >= 4) {
+    TRACE "get_best_parent: related reference cgen=$svol->{node}{cgen}";
+    TRACE "get_best_parent: related older: $_->[0]{PRINT} (cgen=$_->[0]{node}{cgen})" foreach(@c_related_older);
+    TRACE "get_best_parent: related newer: $_->[0]{PRINT} (cgen=$_->[0]{node}{cgen})" foreach(@c_related_newer);
+    TRACE "get_best_parent: snapdir older: $_->[0]{PRINT}" foreach(@c_snapdir_older);
+    TRACE "get_best_parent: snapdir newer: $_->[0]{PRINT}" foreach(@c_snapdir_newer);
+  }
+
+  if(scalar @inaccessible_nodes) { # populated by get_best_correlated()
+    WARN "Best common parent for \"$svol->{PRINT}\" is not accessible within target $target_incremental_resolve \"$resolve_droot->{PRINT}\", ignoring: " . join(", ", map('"' . _fs_path($_) . '"',@inaccessible_nodes));
+  }
+
+  # preferences for parent (and required clone sources):
+  #  1. closest older in snapdir (by btrbk timestamp), related
+  #  2. closest older related (by cgen)
+  #  3. closest newer related (by cgen)
+  #  4. closest older in snapdir (by btrbk timestamp)
+  #  5. closest newer in snapdir (by btrbk timestamp)
+  #
+  my @parent;
+  if(my $cc = shift @c_related_older) {
+    push @parent, $cc;         #  2. closest older related (by cgen)
+    DEBUG "Resolved best common parent (closest older parent_uuid relationship): $cc->[0]{PRINT}";
+  }
+  if(my $cc = shift @c_related_newer) {
+    DEBUG ((scalar @parent ? "Adding clone source" : "Resolved best common parent") . " (closest newer parent_uuid relationship): $cc->[0]{PRINT}");
+    push @parent, $cc;         #  3. closest newer related (by cgen)
+  }
+  if(my $cc = shift @c_snapdir_older) {
+    unless(grep { $_->[0]{node}{id} == $cc->[0]{node}{id} } @parent) {
+      if($c_rel_id{$cc->[0]{node}{id}}) {
+        DEBUG "Resolved best common parent (closest older btrbk timestamp, with parent_uuid relationship): $cc->[0]{PRINT}";
+        unshift @parent, $cc;  #  1. closest older in snapdir (by btrbk timestamp), related
+      }
+      else {
+        DEBUG ((scalar @parent ? "Adding clone source" : "Resolved best common parent") . " (closest older btrbk timestamp): $cc->[0]{PRINT}");
+        push @parent, $cc;     #  4. closest older in snapdir (by btrbk timestamp)
+      }
     }
-    $uniq{$cand->{node}{id}} = 1;
   }
-  if(scalar @filtered_nodes) {
-    WARN "Best common parent for \"$svol->{PRINT}\" is not accessible within target $target_incremental_resolve \"$resolve_droot->{PRINT}\", ignoring: " . join(", ", map('"' . _fs_path($_) . '"',@filtered_nodes));
+  if(my $cc = shift @c_snapdir_newer) {
+    unless(grep { $_->[0]{node}{id} == $cc->[0]{node}{id} } @parent) {
+      DEBUG ((scalar @parent ? "Adding clone source" : "Resolved best common parent") . " (closest newer btrbk timestamp): $cc->[0]{PRINT}");
+      push @parent, $cc;       #  5. closest newer in snapdir (by btrbk timestamp)
+    }
   }
 
-  if(scalar @resolved) {
-    DEBUG "Resolved best common parent (" . (scalar @resolved) . " total): " . $resolved[0][0]->{PRINT};
-    my $parent = shift @resolved;
-    $$clone_src = \@resolved if($clone_src);
-    return ($parent->[0], $parent->[1]->{node});
-  } else {
+  # assemble results
+  unless(scalar @parent) {
     DEBUG("No common parents of \"$svol->{PRINT}\" found in src=\"$resolve_sroot->{PRINT}/\", target=\"$resolve_droot->{PRINT}/\"");
     return undef;
   }
+
+  my @extra_clones;
+  foreach my $cc (@c_related_older, @c_related_newer, grep { not exists($c_rel_id{$_->[0]{node}{id}}) } (@c_snapdir_older, @c_snapdir_newer)) {
+    push @extra_clones, $cc->[0] unless(grep { $_->[0]{node}{id} == $cc->[0]{node}{id} } @parent);
+  }
+  DEBUG "Resolved " . (scalar @extra_clones) . " extra clone sources";
+  if($loglevel >= 4) {
+    TRACE "get_best_parent: parent,clones: $_->[0]{PRINT}" foreach(@parent);
+    TRACE "get_best_parent: extra clone  : $_->{PRINT}" foreach(@extra_clones);
+  }
+
+  my $ret_parent = shift @parent;
+  my @clone_src = map { $_->[0] } @parent;
+  $$ret_clone_src = \@clone_src if($ret_clone_src);
+  $$ret_clone_src_extra = \@extra_clones if($ret_clone_src_extra);
+  $$ret_target_parent_node = $ret_parent->[1]{node} if($ret_target_parent_node);
+  return $ret_parent->[0];
 }
 
 
@@ -3765,7 +3815,8 @@ sub macro_send_receive(@)
   my $source = $info{source} || die;
   my $target = $info{target} || die;
   my $parent = $info{parent};
-  my $clone_src = $info{clone_src};  # arrayref of [ vinfo, correlated_target_node ]
+  my @clone_src = @{ $info{clone_src} // [] }; # copy array
+  my $clone_src_extra = $info{clone_src_extra} // [];
   my $config_target = $target->{CONFIG};
   die unless($config_target->{CONTEXT} eq "target");
   my $target_type = $config_target->{target_type} || die;
@@ -3796,11 +3847,14 @@ sub macro_send_receive(@)
       ABORTED($config_target, "No common parent subvolume found, and option \"incremental\" is set to \"strict\"");
       return undef;
     }
+    # add extra clone_src if "incremental_clones" is set
+    my $ic = config_key($target, "incremental_clones");
+    push @clone_src, map { --$ic < 0 ? () : $_ } @$clone_src_extra if($ic);
   }
   else {
     INFO "Creating full backup...";
     $parent = undef;
-    $clone_src = undef;
+    @clone_src = ();
     delete $info{parent};
   }
 
@@ -3809,7 +3863,7 @@ sub macro_send_receive(@)
   my $raw_info;
   if($target_type eq "send-receive")
   {
-    $ret = btrfs_send_receive($source, $target, $parent, $clone_src, \$vol_received);
+    $ret = btrfs_send_receive($source, $target, $parent, \@clone_src, \$vol_received);
     ABORTED($config_target, "Failed to send/receive subvolume") unless($ret);
   }
   elsif($target_type eq "raw")
@@ -3967,12 +4021,16 @@ sub macro_archive_target($$$;$)
   my $archive_success = 0;
   foreach my $svol (@archive)
   {
-    my $clone_src;
-    my ($parent, $target_parent_node) = get_best_parent($svol, $sroot, $droot, clone_src => \$clone_src);
+    my ($clone_src, $clone_src_extra, $target_parent_node);
+    my $parent = get_best_parent($svol, $sroot, $droot,
+                                 clone_src          => \$clone_src,
+                                 clone_src_extra    => \$clone_src_extra,
+                                 target_parent_node => \$target_parent_node);
     if(macro_send_receive(source => $svol,
                           target => $droot,
                           parent => $parent,  # this is <undef> if no suitable parent found
-                          clone_src => $clone_src,
+                          clone_src          => $clone_src,
+                          clone_src_extra    => $clone_src_extra,
                           target_parent_node => $target_parent_node,
                          ))
     {
@@ -6097,12 +6155,16 @@ MAIN:
                 }
 
                 INFO "Creating subvolume backup (send-receive) for: $child->{PRINT}";
-                my $clone_src;
-                my ($parent, $target_parent_node) = get_best_parent($child, $snaproot, $droot, clone_src => \$clone_src);
+                my ($clone_src, $clone_src_extra, $target_parent_node);
+                my $parent = get_best_parent($child, $snaproot, $droot,
+                                             clone_src          => \$clone_src,
+                                             clone_src_extra    => \$clone_src_extra,
+                                             target_parent_node => \$target_parent_node);
                 if(macro_send_receive(source => $child,
                                       target => $droot,
                                       parent => $parent,  # this is <undef> if no suitable parent found
-                                      clone_src => $clone_src,
+                                      clone_src          => $clone_src,
+                                      clone_src_extra    => $clone_src_extra,
                                       target_parent_node => $target_parent_node,
                                      ))
                 {