Just to be sure you know, there is no necessity to preclear drives. Some people like to use this plugin to test new drives before installing them in their array, but UnRAID will clear new drives when they are added to the array.
IIRC, exFAT should also work. You might want to test it though, just to be sure. Format it in unRAID, add some sort of test file, then hook the drive to your Mac and be sure you can read/write to the file.
Just from looking at that GitHub link, it appears that you are trying to use a python 2 plugin with the latest version of Deluge which uses python 3. This plugin (along with more than a few others) must be updated to python 3 before you can use it. You can use tagging in the docker configuration to roll back to a previous (python 2) version of Deluge if you want.
The full tag doesn't show in the screenshot, but it's binhex/arch-delugevpn:1.3.15_18_ge050905b2-1-04
Edit: Some people have lost torrents when rolling back. Be sure you have a backup of the docker to restore from.
Whatever container path you set in the docker configuration should match exactly to what you use in Plex settings. If the container path is /transcode then you would enter /transcode for your transcode location in Plex. This will result in transcoding in whatever host directory you have configured in the docker. /mnt/user/transcode in your example.
I believe you can also still stop your Mac from creating these files.
https://www.google.com/amp/s/www.techrepublic.com/google-amp/article/how-to-disable-the-creation-of-dsstore-files-for-mac-users-folders/
I don’t use this, so not sure if it still works with recent macOS’s.
You could test with APFS, but I doubt unRAID supports that. Probably HFS+ is going to be your best bet.
Paragon Software offers extFS for Mac which would also allow you to use EXT. I don’t think there is any sort of free version though.
I was surprised to see that this script starts a parity check when you run it. Is this normal?
Edit: Tried canceling the parity check, but it just restarted when the next test started.