Thanks for the insight! - I am probably going with the Kflop option.

Is this your machine on the Dynomotion YouTube channel? It sure looks awesome if it is! https://www.youtube.com/watch?v=qfY4WMXaTAw

I just found the Zip files you shared on the first page of this post that is quite a bit of info.

LinuxCNC +Mesa is the other option I am considering, but it seems like it would always have more latency in the servo control loop vs the Kflop all firmware system controlling motion.

The Kflop user interface is a little rough around the edges, I have seen the editor but there is only so much it can do it seems.

Do you have any pictures of where the analog torque control wire is on your axis drives? that would help a ton

Also a new copy of your Kflop software setup would be amazing

I am very impressed with your diagrams showing how you seem to have used all the hardware sensors on the machine - I don't think most people are as thorough in their conversions.

The code in your ToolChange.c file is very well commented and looks great!