Kind of complicated. Why not return as soon as you fail to find any method?

sub does {
    my ( $proto, @method ) = @_;
    return if ref $proto && !blessed $proto;
    my @does;
    push @does, $proto->can( $_ ) || return foreach @method;
    return wantarray ? @does : \@does;
}
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That said I think diotalevi’s Params::Validate recommendation is spot on.

Makeshifts last the longest.