Something is wrong. The device should have rebooted 30 sec after it finished first boot. Do you have SuperSU?
Also in all of my testing I have flashed it IMMEDIATELY after a reset. So it would reboot while at the blue welcome screen
Removed lastpmver.txt then rebooted with result: The script did finally reboot it 1-2 or more minutes later.
Looks like it was delayed from how slow the tablet is running. Initial os speed after further reboot is still unusably slow, improving after a few minutes and greatly for each downloaded app after first run.
Further reboots show initial os speed may be increasing. Though initial non-system app open speed can still be counted by 10s of seconds and Activity creation can be a bit slow as well (also initially). App resume speed is normal or close to and usage of app following resume is as well.
Before, the apps were [to me] constantly unusably slow - even android settings was super slow. So the mod has definitely made a great improvement.
Wiping cache via twrp result: A little to nothing.
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