"Fixed iteration" DiffEq solvers on the GPU?

Hey, I am currently trying to (re)write some old hobby project into Julia (related to raytracing) and want to rely on the DiffEq solver interface, ideally inside a KernelAbstractions.jl kernel (as I am performing a lot of operations during and after solving that can not easily be expressed through the ensemble or callback API (without losing out on performance), but still want to stay on the GPU). After some initial benchmarking, a problem I noticed was that ray bundles were having warp diverg...