i admit i was a little unsure what to do with the update you posted (it wasnt an IMG file that could be burned to an SD card).
so i took an SD card that i burned with the latest v12 nightly image, mounted it on a linux PC and replaced the SYSTEM and KERNEL files with the files from the "target" folder in the tar you posted. It booted up and was now reporting that it was running your development version. Did I do that correctly?
Anyway it ran fine and was working, including CEC. But I left it idle though and it froze after about 20 minutes. After a power cycle it it immediately says "[SKIP] Ordering cycle found, skipping local-fs.target" and sits there.