The "Perl uses a NFSA" statement is not strictly true. So-called regular expressions in Perl accept languages ordinary FSA's cannot.

/^(.+)\1$/ matches a string iff its second half is the same as its first. It is fairly easy to show (via the Pumping Lemma, or even a simple counting argument) no FSA can match this class of strings.

So, even if an optimizer existed (and they do), it probably wouldn't be directly applicatible to Perl pattern matching.