Hi trainer-living,
I hope the admins can clear your account soon. I have to move it to the Q&A forum now.
Spline selelctions and material selection, I'm not aware that there is a connection.
Try this
https://stcineversityprod02.blob.core.windows.net/$web/Cineversity_Forum_Support/2024_PROJECTS_DRS/20240208_CV4_2024_drs_24_HAal_01.zip
You can see that I have set the Generate to something that creates Polygons. When this is turned into an abc file, you can create a copy and make it editable until you get polygons. These polygons are selectable and can be stored in a Selection tag. This tag can be used on the abc import. As long as no polygons change (change of amount or length, etc. Then, those can be used for Material tags.
Other than that, I have currently no idea.
I will move the thread to the Q&A; we can take it from there. Sorry, but the Site Issue site can't be the backdoor for questions.
All the best