I've been using Penultimate to take notes in classes and do research especially with the split screen functionality on my iPad Pro. Unfortunately, Penultimate has a problem with the position it tracks the Pencil on the screen, when the app is on the right side of the split screen. The tracking of the Pencil is such that it draws the Pencil trace about a centimeter below the Pencil. This makes it quite hard to use the Pencil as a writing or a drawing tool, and negates much of the convenience of using the same tool for note-taking and research.
It works perfectly well, when Penultimate is the only app or it is the app on the left side of the split screen view. It's only when Penultimate is on the right side that the Pencil tracking is off-kilter. As the tracking seems to be off only in this instance, could you recalibrate the app for this eventuality?