What you are doing with DifferentialEquations.jl might well end up being the LAPACK of ODEs: a comprehensive, well-organized library that forms the basis for basically everything in the topic going forward.
I do still find value in rolling my own, for my own understanding and for teaching others, and for agility in problem-solving that comes from pairing broad knowledge of math, good skills with a general-purpose language.
I think it’s time for me to dive into and wrap my mind around DifferentialEquations.jl and SciML. I should understand what you’ve done instead of speculating about it! And I’m sure it’ll teach me all sorts of things about how to use Julia.