I'm quite fond of differential forms, but the first time that they came up in my undergraduate math major was late in an optional second semester math analysis

I'm quite fond of differential forms, but the first time that they came up in my undergraduate math major was late in an optional second semester math analysis course (and even the first semester of of that course was more advanced than what a lot of undergraduate math programs seem to reach), and the treatment in that class was very brief. I take it from your question that you think that there's a way to incorporate the differential forms formalism for electromagnetism into an undergraduate physics major at roughly a 2nd-year level (or maybe 3rd year). I'd be really curious to know what you have in mind: I teach physics professionally, and I have trouble imagining how to do forms justice in a way that matches the intuitive grounding of div/grad/curl (which many students already struggle with, mind you).