DDT Match Reporting differences

my regex xxx  { $<t1> = aa  $<t2> = a  a } ;
> my $dump_1 = $d.get_dump(title => "$string ~~ " ~ 'xxx', $string ~~ m:g/<xxx>/ );
aaaaaaaa ~~ xxx (2) @0 (List|215006672:DDT:-1254517668)
|- 0 = 'aaaa' [0..4|.Match @1 (Match|xxx(Match|t1(Match)t2(Match)):DDT:-1254516752)
|  `- xxx => 'aaaa' [0..4|.Match @2 (Match|t1(Match)t2(Match):DDT:-1254515940)
|     |- t1 => 'a' [0..1|.Match @3 (Match:DDT:-1254515032)
|     `- t2 => 'a' [2..3|.Match @4 (Match:DDT:-1254514480)
`- 1 = 'aaaa' [4..8|.Match @5 (Match|xxx(Match|t1(Match)t2(Match)):DDT:-1254513016)
   `- xxx => 'aaaa' [4..8|.Match @6 (Match|t1(Match)t2(Match):DDT:-1254512204)
      |- t1 => 'a' [4..5|.Match @7 (Match:DDT:-1254511296)
      `- t2 => 'a' [6..7|.Match @8 (Match:DDT:-1254510744)

======= Note extra elements for $dump_2 =======

my regex yyy { ($<t1> = [aa] ) ($<t2> = a) a } ;
> my $dump_2 = $d.get_dump(color => False, title => "$string ~~ " ~ 'yyy', $string ~~ m:g/<yyy>/ );
aaaaaaaa ~~ yyy (2) @0 (List|198521408:DDT:-1253000904)
|- 0 =
|  |  'aaaa' [0..4|
|  |  .Match
|  |  @1
|  |  (Match|yyy(Match|(Match|t1(Match))(Match|t2(Match))|(Array|214945352)):DDT:-125299
|  |  9988)
|  `- yyy =>
|     |  'aaaa' [0..4|
|     |  .Match
|     |  @2 (Match|(Match|t1(Match))(Match|t2(Match))|(Array|214945352):DDT:-1252999176)
|     |- 0 => 'aa' [0..2|.Match @3 (Match|t1(Match):DDT:-1252997744)
|     |  `- t1 => 'aa' [0..2|.Match @4 (Match:DDT:-1252996932)
|     `- 1 => 'a' [2..3|.Match @5 (Match|t2(Match):DDT:-1252996168)
|        `- t2 => 'a' [2..3|.Match @6 (Match:DDT:-1252995356)
`- 1 =
   |  'aaaa' [4..8|
   |  .Match
   |  @7
   |  (Match|yyy(Match|(Match|t1(Match))(Match|t2(Match))|(Array|214945392)):DDT:-125299
   |  3356)
   `- yyy =>
      |  'aaaa' [4..8|
      |  .Match
      |  @8 (Match|(Match|t1(Match))(Match|t2(Match))|(Array|214945392):DDT:-1252992544)
      |- 0 => 'aa' [4..6|.Match @9 (Match|t1(Match):DDT:-1227329040)
      |  `- t1 => 'aa' [4..6|.Match @10 (Match:DDT:-1227329212)
      `- 1 => 'a' [6..7|.Match @11 (Match|t2(Match):DDT:-1227329520)
         `- t2 => 'a' [6..7|.Match @12 (Match:DDT:-1227329924)