So after installing Sierra (sorry, there's no HP Envy topic in the Sierra laptop forum, so I've posted here) I managed to fix WiFi but a few issues still remain.
Obviously I'd love to get the function keys working, but this seems to be a problem universal to all hackintosh PCs on Sierra and not unique to this device. I'm not sure when or if it will ever get fixed (hopefully so!)
I have an Apple LED Cinema Display which I always use with my Envy. It has a resolution of 2560x1440 and works great in El Capitan. In Sierra however, the max resolution shown is 1280x720. It looks abysmal. HDMI Audio also doesn't seem to work, but that doesn't really matter since the Cinema Display has a USB cable for audio anyway, which works fine. I've tried using the Option + Scaled button, but that just brings up an alternate resolution of 800x600 (great!)
Second, I haven't managed to get internal audio (microphone and two speakers) working with AppleALC. I've gotten it working on Sierra before, but I can't seem to find how I got it working. Perhaps it was a forked version of AppleALC or perhaps an update to 10.12 broke it.
The external monitor resolution is obviously my highest priority at the moment since it looks worse than the built in laptop display. If I can't get it working, I'll be switching back to 10.11. Any ideas Rehab?