"p.s. maybe the latest perl should allow "0x41"->$* ? (tongue-in-cheek)"

It does, but it doesn't work how you think it does. That's called postfix deref, and it only dereferences a reference. A string (which is what you have) is not a reference. Here's an example of using postfix deref after assigning your string to a scalar reference:

perl -wMstrict -E 'my $x="0x41"; my $y = \$x; say $y->$*'
0x41
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We don't often see direct scalar refs though. Makes more sense with a struct:

perl -wMstrict -E 'my $href={a=>1}; say $_ for keys $href->%*'
a
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Which is the equivalent of the circumfix deref operator, which is by far more common (postfix deref was just released from experimental status in 5.24.0):

perl -wMstrict -E 'my $href={a=>1}; say $_ for keys %{ $href }'
a
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...or more simply as we're using the whole thing, and not just a piece of it:

perl -wMstrict -E 'my $href={a=>1}; say $_ for keys %$href'
a
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