Hi,
first of all thank you to the Streamlit team & community for the wonderful work around this library!
I have been trying to make things work using Streamlit concerning the pythonocc library (a python wrapper of the OpenCascade CAD Kernel), and I finally manage to make it functionnal trough a little trick using the pythonocc’s webserver.
You can find a sample code with a wonderful example here : 
I guess we could make it more efficient, instead of reloading the webserver at each rerun of streamlit, but it’s a first try.
I didn’t try to turn it to a component because of the conda env needed from the pythonocc side.
I would be happy to get people trying to get it the right way with me!