converting is one thing, reworking, or rebuilding is quite another,Erm - ask @Zwiss ? It takes ages to properly convert a track for example. (Though he's rebuilding many things as well.)
I don't know what conversion method you use, but converting directly, without reworking the track mesh or anything else, i.e. 1:1 conversion, doesn't take much time, always depending on the track and the number of objects.I whish conversions were like that, but yeah.. saying it's yours isn't cool too.
What I do with 3dmax is massive renaming, I first select the mesh of the track, all the objects that compose it, then I rename mesh, with prefix, suffix and number, then I hide that mesh, then I do the same with the grass, I hide that mesh, and the same with the collisions.
It usually takes more time to give values to the shaders in the kseditor