hot take: i don't think you even need to understand much linear algebra/calculus to understand what a transformer does. like the math for that could probably be learned within a week of focused effort.
Yeah to be honest its mostly the matrix multiplication, which I got in second year algebra (high school)0.
You don't really need even need to know about determinants, inverting matrices, Gauss-Jordan elimination, eigenvalues, etc. that you'd get in a first year undergrad linear algebra