Lost H265 needs expanding on because kszaq specifically refers to hevc now working at 4k in the very first post on this forum. I'd suggest you have a read of the section on how to report bugs ( with logs etc). I can play H265 on a box with S805. With the correct tone you will find him to be very supportive.
Can't help you find your Android firmware to reinstall but I have to point out that if you'd installed to SD first and gone down the dual boot route, android would still be there for you. I know it doesn't help but it is the risk free way to follow when you've got android back.
Yea, I tried the SD card thing first but it didn't work. It just always booted into recovery. So I thought maybe I was supposed to "Install from EXT". I guess not. The H.265 doesn't work in the same way it didn't work on my Pi. It stutters, is glitchy and there is no sound. I have a S905 though. Admittedly, I do not know much about these Android machines. I have like 5 RPI's, but this is my first Android box. I got it just because the RPi's couldn't do H.265. It's just been a LONG day. I could never get the storage to expand to the USB when it was Android and there was too little room for Kodi to play correctly. Then I put on LE and lost the H.265. This new box hasn't been as much fun as I thought it would be! I'm ready to flush it down th toilet.