Hi Tim,
Yes. The clone was necessary because ICU takes ownership of the UNumberFormat passed to it. And yes, this would be unexpected. Technically it is possible for us to fix this in the php side. My idea is to make the internal ICU formatter refreshed lazily before the next format() or formatnumeric() call, and by refreshing we observe if there is updates to the internal retained numberformatter. I think this is a good catch user-side. Will add this in the RFC and implementation. Thanks! Weilin
