This should be what you want. A couple of stubs and fake names shown to give you ideas for how to fill in the blanks. :P The new helper component–

package MyDB::Audit;
use parent qw( DBIx::Class );
use strict;
use warnings;

sub update {
    my $self = shift;
    return $self->next::method(@_)
        if some_reason_not_to_log_this_one($self->table);

    my %data = $self->get_dirty_columns;
    _log_changed_data(\%data);

    $self->next::method(@_);
}

1;
[download]

One of your current result source classes–

package MyDB::Result::Dingus;
use strict;
use warnings;
use parent "DBIx::Class::Core";

__PACKAGE__->load_components("+MyDB::Audit");
__PACKAGE__->table("Dingus");
__PACKAGE__->add_columns( ...et cetera... );
[download]

Have fun. :P