Ethan,
I still don't understand. Real space refinement will minimize a fit of model to density in whatever map you give it. It's up to you which coefficients are used to calculate the map you are refining against.
This is true.However, I guess, the way it is implemented in Coot is a bit different (Paul, please correct me if I'm wrong).
Compare slides #4 and #5: http://cci.lbl.gov/~afonine/rsr.pdf Pavel.