Other than this documentation, we won't support Mach3 with the TMC3in1. It is not worth our time or your time. Please just believe us and use Mach4 and SheetCam with the TMC3in1. Click here for more info on why.
The TMC3in1 plugins may be found here:
The TMC3in1 is a Torch Height Controller that plugs on top of the ESS, and commands velocity based up and down moves for your Z axis to achieve the optimal cut based upon your settings. This is also a BOB (Break Out Board) that provides 8 additional outputs (for up to 4 motors/axes) and 2 additional opto-isolated inputs.
Please read through all of our documentation on this site.