I always thought the notation of differentials is a footgun:

https://books.physics.oregonstate.edu/GMM/notdiff.html

Why "Geometry"? Seems to just be a math 101.

It'd be nice to incorporate links to Demos-3D to supplement visualizations of complex number algebra and 3D vector/matrix ops: https://www.youtube.com/playlist?list=PLfM6zMGnbgOHoJFFgqQ4O...