Ok, I couldn't resist!

add:

use Algorithm::Diff;
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toward the start. In sub add change:

        push @{$context->{tails}}, $line;
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to:

        push @{$context->{tails}}, [$line =~ /(\S+)/g];
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In sub mergeTails replace everything after:

    my @groups;
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with:

    push @{$groups[@$_]}, $_ for @tails;
    @groups = grep {defined $_} @groups;
    
    for my $group (@groups) {
        my @ref = @{$group->[-1]};
        my @org = @ref;
        my $count = 1;
        
        pop @$group;
        
        while (@$group) {
            my @new = @{pop @$group};
            my @diffs = Algorithm::Diff::diff (\@ref, \@new);
            
            for my $change (@diffs) {
                next unless $change->[0][0] eq '-';
                $ref[$change->[0][1]] = undef;
            }

            ++$count;
        }

        for (0 .. $#ref) {
            next if defined $ref[$_];
            $org[$_] = '*****';
        }
        
        push @{$context->{digest}}, [join (' ', @org), $count];
    }
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Now prints:

infocache02
    ldap_cachemgr
        (1) Error: Unable to refresh from profile:tls_automount_profil
+e. (error=1)
        (1) libsldap: Status: 91 Mesg: openConnection: simple bind fai
+led - Can't connect to the LDAP server
    sendmail
        (3) ***** Losing ***** savemail panic
        (2) ***** SYSERR(root): savemail: cannot save rejected email a
+nywhere
mail2-in
    postfix/smtpd
        (2) warning: 84.9.96.201: address not listed for hostname mail
+.intechcentre.com
        (4) warning: ***** hostname ***** verification failed: hostnam
+e nor servname provided, or not known
mail2-out
    ntpd
        (5) ***** Bad file descriptor
    postfix/smtp
        (1) warning: valid_hostname: empty hostname
        (1) warning: malformed domain name in resource data of MX reco
+rd for hotmil.com:
    postfix/smtp[32282]
        (1) warning: numeric domain name in resource data of MX record
+ for uyahoo.com: 10.0.0.2
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