Got the same board running Armbian with ChatGPT. Because we performed a lot of experiments, here are summary of how we actually got it running
tl.tr: upgrade_tool is wonderful, but running it on my board destroyed everything and I had to recover from backups.
We backuped board completely, then intentionally corrupted android bootloader from adb and managed to get U-Boot running via modification of boot.scr
Here is a chat-gpt generated summary: