I believe you were provided more than ample information to make an informed decision that there is no Kadee, or any other for that matter, coupler that will mount or function in the USAT molded in coupler pocket. It is totally cosmetic.
As for getting dimension out of Kadee, good luck with that. I spent over an hour on the telephone with them requesting similar information to use building Solid Works solid models of rolling stock. I was clearly told in no uncertain terms that the information was 'proprietary'. I then spent an evening measuring and modeling an 820 and 830 coupler and box to meed my needs.
As to your comments about some of the folks on this forum, I find your statements to be totally out of line. You requested information that is NOT READILY AVAILABLE. Folks responded with their knowledge and experience. I am sorry it didn't meet with your approval. Apparently the folks over on MLS didn't have the answer to suit your desires either. I am also sorry that MLS, your home base, is slowly falling into a death spiral, but don't take your frustrations out on folks here. Take the information that suits you and ignore the rest, just don't attack the members here, the result may not be pleasant.
Good luck in your dimensional search, however I recommend you purchase the couplers in question and get out your calipers as I did.