An osc “command” is an adress, ex. “/sequencer/knob1” followed by properties of type string, int32 or float32 (and more - see OSC spec 1_0 )
https://openstagecontrol.ammd.net/docs/widgets/properties-reference/
In Open Stage Control, there’s an encoder widget that can send ticks, -1 or +1 integers depending of the direction of turning.
Or you can develop your own controls, using XY widgets (that can be made invisible) and scripting.
https://openstagecontrol.ammd.net/docs/widgets/properties-reference/#encoder