I don't think YAML's unreliability has anything to do with the size of structures. Parsing YAML seems to be too difficult for YAML.

YamlFoo

#!/usr/bin/perl

  use strict;

  use Data::Dumper;
  use YAML qw(Dump Load);

  my $before = {

    ok => [
      {one => 1},
      {two => 2},
    ],

    not_ok => [
      {-one => 1},
      {-two => 2},
    ],

  };

  my $after = Load(Dump($before));

  print Dumper $before;
  print Dumper $after;
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