I have a long time (15 years) using Sketchup for my 3D and archviz models. For rendering I use Thea render from the first version, I was also a V-ray tester for Sketchup.
Including complex models through proxies is very important.
For this I use Transmutr, a really useful and easy-to-use tool, a couple of clicks are enough to include any complex OBJ, FBX, SKP model.
Right now it supports proxies for: Thea render, V-ray and Enscape.
They are great guys, and I think there is a chance for collaboration to support D5 proxies in the future. It would be great!
Proxie skp model: