No one defines a direction to turn the rotator. All the ASCOM platform allows is the ability to specify the angle and it’s up to the rotator on how to get there. So if you’re at 90 and you tell it to go to 45 and that has different results between applications then something is likely up inside of the application. Having said that, SGP does allow you to sync a rotator to a specific sky angle and will use that as an offset to get to different locations. This has been in for a while and is working with a multitude of other rotators though. So I would find it odd to not be working with the Pegasus rotator.
Also, no where does ASCOM specify a direction for a rotation. So if you’re at 0 and you ask the rotator to go to 45 it can go clockwise or counter clockwise and either of those are fine. Thus most Rotators provide the option to switch the direction so that everything lines up.
Jared