Can I customise the winders on stairs to turn on a point, rather than the default 'balanced' style.
Yes when drawing a component stair with winder, place it, and select the stair component click on the properties and change the Winder Style to 'Single Point'
You can then specify the number of parallel treads, thereby adjusted the point which the winder operates.
(NB. for some stair layouts you will still have to use the sketch mode, or use the convert to sketch option)