Also I just found the capability in both OneNote and Word to define my own shorthand for equations so I can input equations about 10x faster than the default functionality (e.g. instead of \partial/partial\phi, I defined it as \pphi, since I use this all the time in my equations).

This adds so much capability to the equations and it would be really awesome if we could define our own shapes based off of custom strokes. Maybe you are already planning on doing this (or maybe it is not feasible), but just wanted to point out that it would add SO MUCH to the awesome shape recognition that you just added/described.