You can specify an arbitrary block on the command line with a Maori farewell like this:

perl -M'5;BEGIN{eval{require Internal::Module}}'
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It is a little bit tricky to embed this in PERL5OPT but maybe it is something you are looking for.

$ PERL5OPT="-M5;BEGIN{eval{require(Internal::Module)}}" perl -MO=Depar
+se -e0
sub BEGIN {
    require 5;
    ()
}
sub BEGIN {
    eval {
        do {
            require Internal::Module
        }
    };
}
'???';
-e syntax OK
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