Thank you again for all your answer, Mark!

For that particualr path no amount of Surface Fidelity seems to help. I was able to separate the working portions and import the others as separate figures, but then my Carrara is acting weird lately, and I can't quite figure it out. (I just posted another question about it.)

(Sorry for the delayed response, I got swamped by life and work and only now got back to testing things in Carrara.)