Hood, I've taken the plunge on one of those po-mo minithcs from Denis, and I had a good discussion with him about the caxis protocol.
Long and the short he has expanded the c-axis protocol which has reduced the amount of data required to send the TH voltage setpoint to the controller.
I have been playing around with a sheet cam post processor and sort of cut pasted, and created my own for the po-mo minithc which allows you to store the voltage setpoint with the tool, and send it to the controller under tool change.
I also now have a pmx 45, and noticed an error in the manual regarding feedrate in the conversion from in/min to mm/min but this has allowed me to create few feedrate equations that match the pmx manual settings. All you do is tell it the material, thickness and ampage (30/45) and it will work out the feedrate directly in sheetcam... Must admit not finished the function on this one in the post processor.... And it's only for the pmx45.
Rob