Diffusers is pretty well done (I think the author was basically rewriting some Julia libraries and adapting them to JAX). I can’t imagine it being too hard to adapt most SciML ODE solvers.

For simulations, JAX will choke on very “branchy” computations. But, honestly I’ve had very little success differentiating through those computations in the first place and they don’t run well on the GPU. Thus, I’m generally inclined to use wrappers around C++ (or ideally Rust) for those purposes (my use-case is usually some rigid-body dynamics style simulation).