Hi Daniel -
No. In any shaded display modes, NURBS objects are represented by their “render meshes”. These are generated on the fly and are what you see on screen. Using ExtractRenderMesh lets you extract these as separate objects, and, depending on the settings and number of these, can be quite a bit lighter than the objects they were derived from.
In that case, only using the render meshes won’t work.
That will typically come in as blocks and those don’t necessarily always make sense. It might be better to explode those blocks and move objects into different layers that can be turned on and off as required. Pascal wrote a useful script to automate the exploding and moving to layers part of this:
Hiding anything you don’t need typically is the best way to make files easier to work with.
Again depending on the situation, you could insert a complex file (that is a separate 3dm file), create a dummy block in your working file, and use ReplaceBlock to switch between the dummy and the complex versions.
-wim