@postmarketOS Could buildroot be of any help. I see you guys wrestling to compile the right kernels for the phones - https://buildroot.org/
THis platform is there to fascilitate that compiling and much more crosscompiling. I discovered them via the mailinglist of lowrisc - https://listmaster.pepperfish.net/pipermail/lowrisc-dev-lists.lowrisc.org/2018-September/001046.html
Fosstodon is a Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.