It's already running an almost mainline kernel: https://twitter.com/mntmn/status/1259611758827835394 and what is left looks like it would be easy to get upstreamed. I don't know about the u-boot situation, but one can always ask Lukas on twitter ^^

I have a Novena around collecting dust too and used it a lot while it was still getting patches. I'm actually more excited about the reform2, and already held a prototype unit at 36C3. It's very much what got me excited about open hardware laptops in the first place, but packaged in a more user-centric way. the Novena was always a pita to use on the go.