Hi Paul - thanks again for the response.
The reason it is not proportional is because with a telescope focuser, finite movements are needed & focussing can be down to 1 or 2 step movements. Having it proportional means it is quite easy to miss the right focus point. The way I have the joystick set up is that it takes into consideration the status of the speed steps and no matter how far you push the joystick, it will only move at the speed it is assigned with at that time.
It's mainly through choice using the joystick. I thought it would be easier than using buttons, however I'm happy to try buttons for forward & 1 for reverse, but not sure how to.