@peter-gamma Its different for XDA: Everybody knows that on XDa the community is a fair mix of official and unofficial stuff, with probably more "home-brew" stuff so people wont blame XDA for a non-working ROM right?
XDA community is supporting a vast amount of different Android ROMS, and its up to you what you choose. You are responsible all by yourself.
However, on Ubuntu Touch its a bit different: The community expects basically that whaever we publish is working very well, as our old devices have a good record of being fully usable as daily drivers, at least from the porting point of view. Putting a device into a) devices page, b) installer, c) forum gives it a look of being an officially supported device, and so we want to ensure minimal functionality at last, to not scare away people with semi-finished ports that will never get complete.
So for a porter the motivation should be: If you try hard to get your device at least working to 90% or so, you can get into the installer. We list you on the devices page with "experimental, wip, community device" mark if you are not quite there.
But for the forum? Well its a bit difficult, I agree. We could add all devices "just so", without putting any rules. But I really think that would create a ton of subforums with no traffic, until a device gets more popular, and so its really not worth.
XDA is used by thousands of people daily, we might have a few hundreds. So also from traffic perspecitve I dont think that is really needed.