I've actually been watching it for the last 10 minutes without a scan, and after the rclone mount has been added. Plex is at 2%, max right now (no scans), while streaming a video. I'm going to start every docker one at a time to see if maybe a docker has gone wild.
EDIT: Things were going like they should be until I opened NZBGet. As soon as it opened, the CPU and process shot up and won't subside. Interestingly, this was happening on my previous install...when I was using Sabnzbd.
EDIT EDIT: According to advanced view on the Docker tab, NZBGet is only using 1%. So I'm thinking it's not actually NZBGet after all.
EDIT EDIT EDIT: It just appears out of nowhere 11 minutes after the server is rebooted. I installed the Open Files plugin and it showed me a random video file was open, so killing that has fixed the error. I will keep monitoring.