the H96 Max RK3566 8GB (the very first at 8GB) doesn't even have a SD slot, u-boot nor any uEnv.txt it's a DSU https://developer.android.com/topic/dsu
dynamic software update that can be bypassed but it's totally alien to the solutions we (I) have thus far. I got them rooted though but replacing the OS is gonna be a tough candy
I too made a station image but M-2 (rk3566) not P-2 (rk3568) with the build script, fingers crossed. The RK tools doesn't differenciate 3568 of 3566 in the config files.