It sounds like you're talking about a couple different things, but I'm not entirely sure.
I think you're trying to adjust the trim pots? The manual says 2rps, or 120 rpm.
Where'd you get .2 lead ballscrews in Australia? All the Chinese ballscrews are 5mm pitch, I believe.
For tuning the trimpots, I don't think it's that critical. 120rpm / 5 turns per inch = 24ipm, x25.4mm = 609mm/min
So you can use MDI and simply type G1 X300 F609
Or, you can change your motor tuning velocity to 609 and just jog around at 100% jog rate.