Well I would have answered that what you already said, that you just have to increase the movespeed in general parameters. But well I got another idea. You could let the units run faster per periodic use of
native SetUnitX
takes unit whichUnit,
real newX
returns nothing and
native SetUnitY
takes unit whichUnit,
real newY
returns nothing . Per
native GetUnitCurrentOrder
takes unit whichUnit
returns integer you can prove if the unit move or not. The id for move is "851986".