@JorgeBThank you for taking the time to review the diagnostics in my original post and pointing me in the direction of potential solutions.
The first thing I did was just check on the cables to be sure they were clipped in and secure. I was concerned with temps on the drives as the case's 2.5" mounts were opposite the mainboard and I couldn't visualize how airflow would pass over them in this location and I had an dock for a 5.5 inch pay that holds 4 2.5" drives and decided to put it to use. This allowed me to disconnect, reconnect and be sure the cables were all secure and inspect them while they were disconnected. Everything seemed fine so I put it back together.
Things seemed to still work, but I think the log file growth continued (subjectively speaking) on the same pace. Meantime I upgraded to 6.12.6 and my dockers stopped working. I knew I could no longer pretend there was not a serious issue and I took to time to update the firmware on the two drives.
I have also scheduled the btrfs check hourly. There are loads of resources in these forums.
Again, many thanks for your help.
bkhunraid-diagnostics-20231206-2136.zip