Do what Knife makers do.....
I was thinking with the CBN wheels....
I have a mate (Evan!) who makes a thing called a Noob-grinder for knife makers.
There is an attachment that a knife is magnetically attached to a jig and the item is slid back and forth until the desired finish is obtained.
A knob on the front is wound that moves the jig microscopically back/forth on an screwed inverted trapezium.... this raises it an absolute minute amount... most accurate.
Ive two mates that are kniffy-types and they use their Noob's for almost everything. Very versatile.
I was thinking a jig could be made with drawer runners and a metal threaded bolt to give something similar? Mount the jig under your belt sander, CBN wheeled grinder, or a lathe attachment?
This would be a bodge-up surface grinder :)
https://youtu.be/k62Iu5U4F8Y?t=848
https://youtu.be/kazpKqIWQpA