I tried to follow your guide (using google translate) and downloaded updated archriscv-2023-10-09, and it worked and booted and logged in via serial - thanks!
As I asked about a repo with precompiled packages before, this approach with ArchLinux might work. 
So, I’m currently downloading the entire repo and put it on the SD card /mnt/data, so I can install them right away, and try to get rndis network and sshd working - keep you updated.