Hi Scott,
Firstly, can you verify which model plasma from Hypertherm you intend to interface? I'm assuming it's the Hydefinition HPR260, but let me know if this isn't correct.
The plasma systems operate in a wide range of speeds where from 200 mm even up to 20 meter per minute effective cutting is possible and rapid speed of 50 meter is desirable. Thus increasing the resolution has practical limits. We do not really experience "jerking" as such, but have some cv related problems. With Arc volt height control and Hydefinition cutting applications it is more evident than on the single gas systems like the Powermax range. Remember that if you have set the Arc voltage to acquire a cutting height, the speed is very important, and too slow a speed can cause the torch to maintain an incorrect height and even cause expensive damage. The Hydefinition plasma systems implement an advanced feature to reduce/increase the current proportional to the speed for better corner and small radius cutting, and more transparency to the CNC as to machine state and error codes as well as pressure management for piercing and post flow. The automatic console allows for macro's which will set parameters automatic for different materials. I am not 100% sure of what you require but I will give you the info as you need it. It is possible with Mach3 to communicate with the HPR.
My company is called Multicon and I'm the sole owner. I had a British partner some years ago, but he left the company and went back to the UK.
Cheers,
Whacko