the above has been proven on several devices for ppl contacting me!
Thanks for taken the time to write down the guide
In general that may work on any H815 device but no guarantees. Most important regarding this is: ARB again. If you have ARB > 0 this will brick your device
After you have done the above you will be able to get into the Download mode again to flash whatever you like to restore.
Cheers and have fun