I'm still hoping someone will comment what the officially supported X and the unofficially working X dual show up as on Jolla's site - seems to me if you buy Sailfish X and register the 'wrong' device dalvik etc could work on any phone, but it's especially likely to work if it's a Sony as the vendor ID will match.

As to porting I'm sure someone is trying but I fear the lack of any posts anywhere (as with the compact) means it's not going well. The place to ask is irc...