There is another out-of-tree rtw89 wifi driver at https://github.com/a5a5aa555oo/rtw89.git This version will build on the old 6.1.99 kernel used on nanopi2 and it actually works. Setting regulatory domain works. It is possible to join a 5 GHz network on a DFS wifi channel. But not to create an AP on...
Blinking twice fast every second sounds the heartbeat behavior the LED is configured for once it boots to Linux. So I think it did boot.
What do the ethernet lights do when you plug the cable in?