My rebuild just finished successfully. While searching, I found this old thread: https://forums.unraid.net/topic/132371-unraid-crashes-during-data-rebuild/
So just to eliminate the possibility, I changed out the battery on my motherboard before trying another rebuild. Turns out it worked. Array is back up and 0 errors during the parity check. Thanks to anyone who looked through the logs to see if they could find anything.
