Bigtreetech CB2 and Pi 2 released somewhat recently (April 20th). They use RK3566 and have a lot of nice features. The board and module are intended for 3d printer use but can be used just like any other pi. There is an official linux image on bigtreetech github, and it seems it's a slightly customized armbian. I propose copying that configuration and adding it as a supported board.
This is a bit of a personal tangent, but I was also thinking of how I can submit the device tree files to the mainline linux kernel, would that be a good idea? I'm planning to use or at least try Alpine on the board and it would be nice to have the needed files in the linux package already.