Comment by adgjlsfhk1

I'm pretty sure it is type instability. The faster way to do this would be with something like https://github.com/YingboMa/Unityper.jl which would fix that. The problem with profiling unstable code in Julia is that it makes everything slow so the profiler will just show a big mess of everything being slow. We do need better resources, but I have no idea what they would like like.