Interestingly, I could not even get the “stock” lineage kernel get to boot (after compiling it). I am not sure, what I did wrong.
But the Halium way did work for me. For reference:
@Ingo FYI: After a heavy flashing session, multiple different GSIs, I encountered similar problem like you described, with black screen for example.
Only a complete reflash of a working android image (eOS in my case) did solve the problems.
After that I was able to flash a working ubtouch again.
Thanks for your pioneers work btw. 