Please have a look into this thread:
https://forums.developer.nvidia.com/t/is-there-a-way-to-measure-rt-core-util/168089
I’m not aware that memory traffic in Nsight Compute reports would be partitioned into SM and RT core usage.
The __raygen__ is just one of the functions of the whole kernel and you should be able to see other OptiX device program domains inside Nsight like the __closesthit__ functions inside your raytracing kernel.
Anything reported as “internal” is either the explicit acceleration structure build, which is a completely different kernel, or internal functions inside the raytracing kernel which are not exposed.