Just wanted to mention for anyone using Nuke that as of 11.2v3 it properly supports IPP2 color workflow. You can just drag and drop any .R3D and it will properly read in the full clip with correct IPP2 defaults. Add a Vectorfield (3DLUT) node and assign whichever IPP2 Cube LUT you would like to use and you are good to go.

Great to see how much easier this process has gotten. I can quite easily work with native .R3D files now in all the way through the pipe. DSMC2 Gemini 5K footage in this example.