So I finally finished my Donut!
Everything is great, but I have a question for those who may have built one:
How high did you make the 4 little hold down clamps?
I would assume fractionally shorter that the Donut's clamping ledge, but in the PDF they mention they work like milling table hold downs which would mean they have to be fractionally higher than the ledge and sit at an angle.
For some reason this has gotten my OCD into overactivity

I previously built a 4 bolt hold-down for the original compund base and will probably make something like this for the Donut in the future but for the moment the little clamps are going to have to do.