I ended up using this PC to convert a bunch of audio files for the Zoom F1 project, and actually forgot that I was having issues with the OS locking up. I haven't been able to narrow down the root cause yet, but the intermittent nature makes me think it might be a hardware issue. For the time being, I will assume the system is unstable and prepare accordingly. When I have some extra money, I'll order a few more SSDs and a M.2 SSD and USB 3 adapter to use for the main boot drive. For now, I will keep running on the old SSD and hope for the best.