Internally the “UI” team is tiny (basically me, a UI/Designer and one or two other part time engineers) and the productivity is astounding tbh
But in hindsight I think flutter-pi or the Toyota one might have been a better investment. The lead engineer in Sony behind the elinux project left for Nvidia. The Toyota one uses Wayland, you can't make it directly hook into DRM. So you'd need a minimal compositor to get it running.
I just didn't like the lack of control you got with the sony embedder, you couldn't specify which display you wanted to show on when using DRM and it was real pain to get it working.
I didn't know about the systemd dependency, but we actually needed it though even though we used Sony because of our dependency on DBus.
Knowing Google, this happening is almost a guarantee. You should consider moving to another framework with a longer shelf life.