The bearing on the Pro will accomodate up to 3/4" thick control panels. There is a spacer under the knob that rests directly on the sleeve bearing, so when the spinner is installed in thicker control panels the spacer would rest on top of the control panel surface. While this isn't necessarily a problem, it may cause a bit of additional friction that isn't present with thinner control panels.
Alternately, you could do as you suggested and router the underside of the control panel where the spinner is installed for a 3/4" mounting depth.
--OSCAR