In the biblio frameworks we let the possibility to select a specific tab to display subfields. In some part there is code that handles (quite awkwardly) this possibility, but globally Koha is assuming the item's subfields must be in tab 10. I think it would make sense to simplify/clean the code and enforce that on the UI (framework edition): Hide "tab 10" for any fields != 952|995 and display only "tab 10" for 952|995.
For instance, to build the list of item's fields in tools/batchMod.pl 332 foreach my $tag (sort keys %{$tagslib}) { 333 # loop through each subfield 334 foreach my $subfield (sort keys %{$tagslib->{$tag}}) { 335 next if IsMarcStructureInternal( $tagslib->{$tag}{$subfield} ); 336 next if (not $allowAllSubfields and $restrictededition && !grep { $tag . '$' . $subfield eq $_ } @subfieldsToAllow ); 337 next if ($tagslib->{$tag}->{$subfield}->{'tab'} ne "10");