I just give MarginNote 3 on Mac a try and see that it has some errors to be addressed.
For example, the letter f’s (especially in the middle of a word) are converted into ↵ as you can see in below screenshot: “different” becomes “di↵erent”. However, some words with f letters still have correct display, i.e. “flexible”. I think this minor error can be fixed easily.
Another issue I have is with the zoom function. Sometimes I can pinch 2 fingers on the touch pad to zoom in/out a document, but other times it does not perform it. It also quit unexpectedly twice in around 5 hours of usage.
So far I really love the concept and execution of MarginNote 3. It is such a helpful tool for students and I wish to use it more to aid my studying in the long run. As MarginNote 3 does not have a very cheap price tag, I hope it would soon perform better.