Thank you Johnathan / Steve, It is working. Please feel free to close the bug report!
Turns out that it was either failing hardware (an old-ish HP laptop I am becoming acquainted with for a family member), or more likely a failing USB stick, with the definite possibility of a mix of both, though the RAM in here seems fine :) Your suggestions were perfect. This is why I love Debian and its community. Technical excellence, and friendly-quick non-AI responses. I admit I had already tried the suggestions, then wrote the bug report from memory later that night. Please excuse the minor typos. Summary of what was done, if it may help another person in the future: After writing, `sync`. Then, `udisks2 power-off --block-device </dev/xxx>`. And, even, replugging the stick, checking `head -c <num_of_bytes> | sha512sum`, just to make sure it matched the signed and verified checksum of the Debian Live Xfce image that was originally downloaded. All of that checked out perfectly. So, it did throw me off with the weird results I was observing. Besides the fail-safe kernel panic, I was also occasionally receiving squashfs errors that went previously unmentioned. Whatever was, or is, wrong seems to be on my end. More: USB stick is a 16GB MOSDART, and instead of simply zeroing out its original contents, I ran a `shred -n 1 /dev/xxx` on it... I know. Bad for a solid state medium. I also have had no previous experience with this brand. I am reasonably sure the problem has nothing to do with the brand of pendrive, but compatibility can be a funny thing sometimes. Thanks Again, Professor Jeebs