Thanks HSXS and Snaj for your replies.
Imagine this. 1000 hd of Brahman weaners moving through a series of paddocks for 10 miles at say 3 kms per hour (1.88 mph). It takes just under 5.5 hrs with an operator behind and to the side and dogs steering the sides. If the SXS only engages at 3 mph that necessitates 5.5 hrs of start/stop operation which is extremely tedious and very hard on the clutch, if, however the clutch is fully engaged at 1 mph then it is possible to cruise along at the correct speed using throttle to speed up and slow down without the necessity to stop. Also much of the terrain is very rough with fallen timber, tussock grasses and melon holes making a 3- 3.5 mph traverse extremely rough.
Sajnaj, you mentioned a programmer, what is it and is it an option to achieve the result I am looking for?