For test #5 (there’s been so many tests, I think this was #5) of the Pentaflake Tabletop, I modified the clip on the router with a big bushing with plenty of surface area for epoxying, and used some epoxy putty made for gluing metal to metal (JB Weld SteelStik). End result: a really solid bushing, which keeps the clip perpendicular to the z-axis screw.

I modified the g-code (see Hand Editing G-Code for Better Machining), and I added a bungee over the top of the router to keep constant sideways pressure on it.
The test was a success.

The cuts are clean, no burning. And, the depth is exactly the same across the whole piece.