Reduce spindle speed for tool measurement

I do alot of boring and profiling using 10mm Coroplast. The bit of choice is 1/4" O-Flute bit. I just had an issue with a different supplier when the bits received were not 0.250. Since these bits are difficult to measure I’ve decided to add a tool setter to our machine. I have no issue delving into the modifications needed to add a new tool change script but I need to have the spindle rotating at some SLOW rpm to be able to accurately measure the diameter of the bit. Just wondering how I can override the minimum RPM’s of the spindle to accomplish this.

I already take advantage of the “live tool” feature in fusion to post a program to use a pen with 0 rpm to do tracings and have modified the post in fusion. I’ve also have modified the post to use a mist coolant system I’ve installed and these work great!

Just looking if anyone else has tried incorporating tool diameter measurements into their CNC.