Hi all-
I also noticed this board as having favorable price-to-performance and *importantly* availability of inventory in the US. As a result I too wanted to be able to run Armbian on it.
I've managed to get an Armbian build working using the vendor (xunlong/Orange Pi) supplied kernel source and bootloader. I was able to successfully compile and run Bookworm and Trixie including installation to an installed NVMe SSD drive.
I also used some of the work by @Nick A in https://github.com/NickAlilovic/build/tree/Radxa-mainline-WIP as a basis. I tried to keep everything Orange Pi specific out of the "sun60iw2.conf" family file and put it in the board.csc with hope that the family file can be shared by both Radxa and OPi A733 based boards in the future.
https://github.com/armbian/build/pull/9967
Notably missing is support for the GPU or hardware acceleration. Video output still works but it is not taking advantage of the video capabilities of the A733 chip so graphics performance is very limited. Full disclosure: my main use case is for a headless server.