My Idea for Good Notes
Lasso tool should only change the part that's selected not all the connected lines (give another lasso or something which can do that).
Offline mode will be a better change as most of the windows user don't have constant internet.
3.Give an option to pan around the document while using it (Pen off tool should be more accessible with a shortcut).
I like GoodNotes from my first use, and you are doing a great job making it cross platform which will increase the convenience while using GoodNotes.