As Unraid continues to be completely worthless at managing data, I've gone back to the roots which is mergerfs. Thankfully, there's a modicum of thought, and they have a balance utility. Spinning a container and running balance still maintains the data consistency rules of shfs, and automates splitting as appropriate. It's completely unbelievable how terrible mover is, and how it ignores all placement rules.
Of course the container needs to be privileged, with /mnt passed to the cont