I've been working with some large design files that are coming to me as STEP/IGS with a single huge 3D sketch. I can get it to import successfully, but it is essentially unusable. Does anyone have any advice on how to best handle something like that?

I am trying to get it in to eventually project on a surface (3D import --> Convert entities on a plane --> Project on surface).

Just for reference, I am on 2014SP3 with a K600, SSD, 32GB Ram, and a Xeon 1250v2.

Thanks for the advice!