They're speccing an entire phone platform from scratch and not using libhybris so the choices they have are quite narrow. I was thinking more along the lines of finding an existing phone model and running with that and modifying it to match.

Which is exactly what I want to use and abuse. It's exactly what Jolla did and what Intex did. You start with a known working Android phone where all/most of the R&D has been done. That's how you get a cheap, rapidly developed, modern phone.

But, what needs to be carefully done is working out what the base "donor" device spec is so that ports aren't going to see red boxes in the Mer port table.