For whatever its worth, my dual boot is working ok with the exception of the SD direct access issue which I think it’s more of a Google OS system problem. I am fairly satisfied with the basic function of my tablets.
The most problem I have is, in short of buying another Android 5.1 OS tablet to prove my theory that Google is trying to screw its customer, I am stuck with an android system that is somewhat disable.
A6C7 here. I was using Mirek v3.0 happily with the SD card (windows never managed to access it) and suddenly one day I also lost SD access in Android. Every card was reported as 2GB (tried 1GB, 16GB, 32GB, several brands) and obviously never managed to erase, access or write to them.
I flashed latest Teclast Android firmware and I can access it again. I guess I’ll stick with it for now.
Link in case anyone is interested, right from the Teclast website: