Without diving into the regs to clarify, by the sound of it I suspect you are getting a little confused.
If someone is licensed to fly the 210 in your example, you are licensed to fly the 182rg. The CP is not training you for any endorsements or ratings. They still have responsibilities under CAO 82 for check and training, and I do believe that teaching them your SOPs on the 182 is not considered "training" by way of the definition of "training".
Training in the sense of the defined word would be teaching someone without csu/rg ratings to operate an aircraft with such features.