Unfortunately I was not able to work on this topic appropriately and thus could not provide any helpful information.
But in the meantime, others have done a lot of work on this topic. Thank you @uablrek for the link.
So I tried and built a new image (from main branch) after https://github.com/armbian/build/pull/8449 had been merged. I can confirm that the Rock 4SE now boots with this version.
