[Zubersoft]

It might be due to the fact that I'm using Microsoft's Shapes classes to draw the annotations, because when you use their UI framework, that is the only way to draw things. There isn't a draw loop like Android where I can just easily draw things on top of whatever is being rendered. This makes the Microsoft approach considerably slower with very little gain (at least for annotations, for things like link points it makes the touch processing more simple). To improve this performance, I would have to convert the entire framework to something like DirectX so that I could just render everything in a loop. It would use more power potentially, but would also result in faster performance, smoother scrolling, etc. I've been thinking about this more and more, but it's a huge change that would most likely take months of effort and could result in a lot of bugs. I think I need to do it at some point though in order to fix some of the issues users are encountering. Perhaps I should just bite the bullet and do it as part of the annotations rework as I'm changing so much of the annotations framework for that anyways. 

Mike

EDIT:
I just looked through the Win2D documentation for UWP, and it may not be as bad as I thought. I may not even have to change my framework that much. I may experiment with this this weekend and post the results.