there is radxa zero 3w, which on paper is nice looking board. bit dated maybe but still lot fresher than pi zero 2w. the rockchip soc should have decent mainline support and it has been around for a while
how close is the OS distribution for that to actual stock debian?
Yeah, I have a bunch of Radxa zero 3W, with their Rockchip rk3566. 4x A55 is just barely better than the A53 era still plaguing us 15 flipping years latter! Unbelievable. Alas just a hair before modern era of Rockchip, so it's support is much less consistent! But still pretty competent all in all!
Pine's Quartz64 has different peripherals attached but still afaik one of the best ways to track upstream support. It hasn't changed much since Linux 6.1 and I don't know if that's because there's nothing new or the page is just out of date. https://pine64.org/documentation/Quartz64/Development/
Decent support is not good enough. The Rasppi support is kind of an unsurmontable advantage.