> x=My::Class:Name.method arg arg

I suppose you meant x=My::Class::Name.method arg arg with double colon after Class :)

But apart of this, it looks good for me!

I tested the call with -M and -m with a fake module which just print the args of the import() , using my oldest available perl(brew) version.

$ perl -MNew=X=Y::Y::Y.meth,1,2,3 -e'print "$]\n"'
New , X=Y::Y::Y.meth , 1 , 2 , 3
5.006002

$ perl -mNew=X=Y::Y::Y.meth,1,2,3 -e'print "$]\n"'
New , X=Y::Y::Y.meth , 1 , 2 , 3
5.006002
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