JRuby vs MRI vs POSIX locale - does it matter?

A note in advance:
I am still trying hard to avoid offenses.
Pls forgive me, if I fail once in a while!

Now that we got a little surprised by Matz’s statement
on Dow ruby's strftime not attempt POSIX-compliance? - Ruby - Ruby-Forum regarding MRI’s
compliance and interest resp. non-interest in passing through libc’s
“POSIX locale” support …

… what’s the position of the JRuby community in common
and esp. the JRuby core developer team?

Do you try hard to achieve 100% compliance with this concept and its
I.e. voiding libc’s support of the worlds’s locales?

Or do you think it can and should be done better?

Kind regards,