how can I indicate to Module::Install that there are exe files?

Maybe install_script ... ?

At least, this seems to be mapped to EXE_FILES internally:

sub install_script {
        my $self = shift;
        my $args = $self->makemaker_args;
        my $exe  = $args->{EXE_FILES} ||= [];
        foreach ( @_ ) {
                if ( -f $_ ) {
                        push @$exe, $_;
                } elsif ( -d 'script' and -f "script/$_" ) {
                        push @$exe, "script/$_";
                } else {
                        die("Cannot find script '$_'");
                }
        }
}
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