Folks,
Thanks so much to the community here, especially bodhi, I see you tireless helping everyone over the years!
After putting off the move from Arch to Debian for almost a year, I finally had a chance to make the switch!
It wasn't a smooth transition, mainly because I didn't follow the instructions closely... oops!
Here are the 2 steps I took:
1. follow the U-Boot guide here
https://forum.doozan.com/read.php?3,12381. I followed it half way, missing the step to flash the default u-boot envs image... I ended up having to figure out how to reset the environment variables, as what was there, was for my Arch installation, and that was causing issues when trying to boot Debian.
I believe this did the trick, while I was in the serial console.
Env default -a
Saveenv
2. follow the 26 Sep 2021 guide here
https://forum.doozan.com/read.php?2,12096%22. I tried this step three times, first, because I wanted to save my arch installation, I moved all the existing directories from my USB thumb drive to another directory. Then I tried to extract the Debian-5.13.6 files on the drive... it seemed to extract, but for whatever reason, I could not boot. I don't recall what the error message was...
For my second attempt, I used another flash drive, repeated the process, and again, I could not boot. I suspect that the flash drive somehow became corrupted, as it misbehaved when I tried to write to it after the file extraction.
Finally, I backed up my Arch files from my original flash drive, removed all the files and repeated the process... and it finally worked!
It was tempting to try to troubleshoot the error, but in the end, starting fresh was the best thing for me.
For folks putting off the move to Debian, no need to fear... read through the 2 posts carefully and you can do it!
Thanks!