I made a small temporary fix until David can implement a full-fledged one.
1. In the plugin code, on line 47, replace "server.uselegacyworkbenchinteraction true" with "server.uselegacyworkbenchinteraction false"
This fixes the workbench opening issue, and the CraftMenu itself will be available in the workbench container.
2. If you care about the UI appearing slightly in the container, here's a fix (I don't know how exactly David interacts with the UI, I didn't quite understand it, so the fix is a bit weird, but it works):
Replace line 913 with
CUIClass.CreatePanel(ref _baseCraftCui, "baseCraft_main", "Overlay", "0 0 0 0", $"{db[2]}.{db[1]} 0.{db[23]}", $"{db[10]}.{db[1]} 0.{db[10]}", false, 0.1f, 0f, "assets/icons/iconmaterial.mat", $"{db[12]}{db[14]} {int.Parse(db[6]) + 25}", $"{db[7]} {int.Parse(db[11]) + 25}");
I hope I didn't break the rules. If I did, I'm sorry, I was just trying to help.