extern sub is actively being worked on. The technical problem is not the ffi, this is trivial, but to fix the broken attributes architecture beforehand. They are not usable at runtime (variable arguments) and Attribute::Handlers only makes it worse.
Of course cperl is lacking compared to perl6 features, user facing. Because I had to fight first p5p sloth, like broken designs for everything. cow, const, threads, attributes, regex, scalar, arrays, hashes, functions, types, lecical $_, objects, symbols, unicode, build system, warnings, exceptions, the VM, ... http://perl11.org/blog/p5p-incompetence.html is a short overview of the technical problems to be fixed.
Professional use: read cperlpod cperl. No security process and competence, lack of progress, lack of maintainance of critical modules (cpan is fine, p5p and toolchain authors are the problem), no types, no compiler, recommending worst practices to move towards Java, no technical management, just community leaders without any idea what they are deciding, loosing all competent devs in the last decades and with just the remaining dead wood vocally protecting their turf, with the usual racial and more unpleasant slurs of the leadership towards its users and co-devs.
As company you wouldn't want to be associated with them, but their counter propaganda silencing and censoring the critics works well.