I don't know if this has been an issue with anyone else, but with the current version of the mod, as well as previous versions, I've had a lot of issues when sorting my toolbar.
Essentially, sometimes I'll try to move an icon to a folder, and the icon will remain in place, while also copying itself to the folder. I then have to remove the icon from the folder and put it back for it to finally work. Then, after I've finally sorted my toolbar, I either leave the scene and come back, or just relaunch the game, and all of the icons are now unsorted and out of their folders.
I haven't had any issues with the part sorting, and this mod has been great in that regard, but the toolbar issue means that I can't really use that feature of the mod. I'm wondering if anyone knows about this toolbar issue, or if it's just me, since I don't think it's specifically mentioned on the Github.