Why? I'm running an Orange Pi 5+ with a fully generic aarch64 image of Home Assistant OS and it works great. Is there some particular feature that doesn't work on mainline?
for server use you can live with generic images. When you want stuff like HDMI audio out and all, generic images usually won't do.
I use it as a desktop, so I need HDMI and actual video drivers, which were added to mainline like this year.