I would actually be very surprised if this doesn't land in 10.3 on release. It'd be very, very unusual for them to diverge (especially since converting apfs t

I would actually be very surprised if this doesn't land in 10.3 on release. It'd be very, very unusual for them to diverge (especially since converting apfs to hfs live doesn't work). On the other hand, iOS seems like the perfect place to go live first - all filesystem access is by apple, or via blessed APIs - it should present the fewest edge-cases.