I do proofs on the RC and then print on Ilford warmtone or MGIV. Unfortunately, you can't get by without testing. However, I have a RHDesigns Analyzer that I use. Once the exposure is set up for RC I can very easily switch to the other paper type and keep the same basic exposure by using the programmable paper types, comparing the grayscales, or just re-metering the same spots again. It saves a lot of time and a lot of paper. They are expensive (somewhat), but I think well worth it if you are going to be doing enough printing to justify the expenditure. With expensive paper, I think it pays for itself pretty quickly.
Best,
Will