You also need to escape @, and sometimes -. For the latter, consider this:

$ perl -we'use overload q:"":=>sub {print "in stringify"}, q:%{}:=>sub
+ {print "
in hash deref";{foo=>1}}; $x=bless[]; qr/$x\->{foo}/'
in stringify
sthoenna@DHX98431 ~
$ perl -we'use overload q:"":=>sub {print "in stringify"}, q:%{}:=>sub
+ {print "
in hash deref";{foo=>1}}; $x=bless[]; qr/$x->{foo}/'
in hash deref
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