Thank you.
Please note that as you started your preclears with screen sessions, you can't control them from the plugin, just see the progress. This plugin uses another program, called tmux, to run preclear script on background sessions. Tmux is a lot better than screen, mainly when we talk about scripting - we can easily start/stop processes and get a session's output. Therefore you can't stop your current preclear sessions, nor see it's output.
The preclear_disk.sh script version I include in this plugin already has support for the new unRAID notification system. Right now, you will receive notifications through all configured channels, but in a future version I'll add the ability to set which channels to use (email, browser popup and agents).