Be sure to check out the GPenny choices at AliExpress, 4 main bearings and a choice of either steel or ceramic. @Julien documented VFD setup here VFD Parameters (Huanyang model)
@neilferreri has authored tool change capable post processors for Fusion 360 and VCarve. Plus macros for CNCjs for tool changes using the Bitsetter and probing using Carbide’s and other probes.
I use 2” x 1/2” shaft facing mills frequently enough to appreciate the speed control. Although for most other work, especially aluminum, I agree with @gmack, max speed on the spindle.
I’ve been messaging GPenny to up their game by offering 40-60k spindles. No response but we can hope. Maybe if all of us started pestering them they’d come up with one.