They seem uninterested in trying to get their hardware supported by submitting their patches for inclusion in the Linux kernel, and popular distros. Instead, you have to trust their repos (based in PRC).
I would never buy one of these things without upstream kernel support for the SoC and a sane bootloader. Even the Raspberry Pi is not great on this front TBH (kernel is mostly OK but the fucked up boot chain is a PITA, requires special distro support).
I feel like rasp pi has the most community support for everything so I had the intution that most things would just work out of the box on it or it would have the best arm support (I assumed the boot chain to be that as well)
what do you mean by the boot chain being painful to work with and can you provide me some examples perhaps?