Hi Mike
I use 2" to 2 1/2" the norm but sometimes 3 or 3 1/4" ID on the hole saws, some jigs need a bit more torg.that's when I use the 3/8-16 tee-nuts and the big OD ones.
I also use 1/4-20 tee-nuts on the small ones like for T-track items,
and use all thread rod when I need the stud type and a cap nut on top for a locking nut.(jam type).
Plastic knobs can be high in price and sometimes, and I can't find the size I want, I also make my table saw wheels when I need one a bit bigger or smaller the same way but I use a plastic long knob to hang on to and crank it with.
Bj
