I installed pie yesterday (need to flash ruu and after that do ota etc.) and everything is working fine. Hotspot works at 2.4 and 5 GHz, adaway works fine systemless (need to check this option in Magisk), mobile data also works (LTE +, VoLTE). Maybe you did something wrong?
Where is adaptive battery hidden? Only place that I could even remotely find it is in developer options and even then it is just the bucket options for the apps.
---------- Post added at 10:18 AM ---------- Previous post was at 09:43 AM ----------
Anyone who wants to see "Adaptive Battery" in your Battery settings install:
That APK. Then go back into your battery settings and you should now see Adaptive Battery. So it does exist but highly possible HTC "forgot" the APK to "enable" it since this update does look to be a bit "rushed".