I tried, once.
My conclusion: Use Maya.
I don't have Maya, and let me tell you, it was a deep, deep, deeeep dive into areas I haven't been in for a long time.
Outside of the Maya/Renderman interface, it seems to be targeted toward actual studios (no surprise) that have actual technical teams who support a rendering pipeline. Also, it is heavily biased toward Unix/Linux (which I haven't used for nearly 20 years).
I thought it would be fun to be the first person to use Renderman to render an iClone movie, just to say I did it. But it was way, way too much effort. I exported an Alembic file from iClone and imported it into Blender. I asked a few questions on the Renderman forum, questions I thought were basic, but nobody there could help me since I was taking my own path.
I did eventually get a render, but getting the textures in there was a royal pain too.
TIP -- If you read about people having trouble with it, or how to get it working... "IT" is actually a preview tool of some sort. I can't remember exactly what it stands for ("Interactive Tool" maybe?). But they don't always put it in caps, so it is often unclear what they're talking about when then tell you to "start it."
Good luck.
(Edited days later - Merely corrected a typo.)