Jumpy scrolling in OmniOutliner 4.4.1 under El Capitan

I’m noticing some odd herky-jerky scrolling in OmniOuliner 4.4.1. Scrolling via mouse is generally OK, but scrolling by page up/page down is clunky.

The outlines where I’ve noticed this the most have a large mix of font sizes and inline notes, so the item sizes vary greatly.

Has anyone else noticed this behavior?

I just sent them an email with a recording showing a list of 335 lines jumping as I scroll through it in split view.