My screen-going-black issue was solved by adding a bunch of random kernel modules to the initrd, but I did not root-cause it yet. Though my error messages looked different from yours. Regardless, adding modules is a cheap solution to try, before trying more precise debugging. 
For me, when `dispcc-x1e80100` is loaded the screen goes black, but then some other module brings it back.
Here is the exact list of initrd modules I am currently using on my yoga: https://github.com/kuruczgy/x1e-nixos-config/blob/main/iso.nix
(From line 10 and line 97)