Definitely interested - is the mainline situation any better than with ARM?
I’ve been bitten before with a device that “supports” a major distribution, but only if you install our custom pre-built image (good luck auditing what we’ve tweaked) and only with our special pre-built kernel that isn’t even an LTS version, and has a bunch of patches applied to support whatever weird peripherals we decided to throw on the board, and will get exactly 0 updates after the initial release.
Raspberry Pi gets around this by being big enough to get buy in from vendors (Ubuntu distributes a special kernel + firmware bundle), but support for all the other smaller knock offs seem shaky at best