I’m really trying to adapt it, but I'd rather just say experimentation. Now I have a working image, but I wouldn't say it's 100% done.
http://libreelec.dtech.hu/snapshots/20211122/ (Source: https://github.com/dtechsrv/LibreELEC-AML/tree/odroid-c1)
It contains almost all Kodi patches I have used for the boxes, including the fix for the IPTV problem, and I also enabled the dvb-latest driver package. However, the kernel of wrxtasy I used for this build is unfortunately very outdated.
Although I only have this board for 2 weeks. Before that, I only had boxes.
For me, the u-boot is a whole new area, so unfortunately I can't answer your previous questions on the merits either, but all the experience comes in handy. If I understand correctly, you want a native ext2/ext4 partition instead of a squashfs + overlayfs for the system patrition, right?