If you do not need the XML to be reformated and do not mind the empty lines left over after removing those tags, then this will be even more efficient:

use strict;
use warnings;
use XML::Rules;

my $rules =XML::Rules->new(
  style => 'filter',
    rules => {
      '^dob'  => 'skip',
      '^dobs'  => 'skip',
    },
);

$rules->filter( *DATA );

__DATA__
<?xml version="1.0" encoding="UTF-8"?>
    <record category="B" editor="" entered="2000-12-04" sub-category="
+PEP" uid="7320" updated="2018-12-12">
...
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If you wanted to skip only some of the <dob> tags based on their attributes you could do something like this:

my $rules =XML::Rules->new(
  style => 'filter',
  rules => {
    '^dob'  => sub { $_[1]{"xsi:nil"} eq "true" ? '' : 'handle'},
    '^dobs'  => 'skip',
  },
);
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