I've been following the S192 threads on here for a while - I've been one of the fortunate ones (touch wood) so far, as I've not come across the many issues detailed in said threads with my S192.
So, a little late with my contribution, but I have the lastest Shield Hub (4.12.20965591) that I got off my Shield Portable before the last update which now, I suspect, is for Lollipop or newer only as the package won't install on the S192 anymore.
If you want the APK, I can give you a copy?
The S192 K1 looks like it's being abandoned by JXD - but personally, I love it. And would love to see some TLC thrown in it's way. I'm not versed in all the dev stuff, but if I can contribute somehow I will
Fyi (you might already be aware of it) for gamestream, I find Moonlight (root version) much better than shield hub itself, with a typically lower latency at 1080p 60fps setting. I didn't continue my subscription with Geforce Now after the free 3 months trial, so I can't really comment on that.