Marty,
When you build a TR with a cab-1, you can have 3 engines in the consist and make one the front with the F key and one with being the rear one with R key. As for the middle engine, you do not press neither F or R and it will be the middle one.
With train link, it is an extra step in addressing the talking caboose. With a cab-1, you don't have train link but you can access the talk with 2 button presses.
Steve Musso showed me how to set up a engine/talking caboose consist with train link and it does work but I still prefer using a cab-1 to do that step up as it is easier to access the talking caboose.
I have to try out the cab-1 vs. legacy with a talking caboose to once again verify what has happened in the past while demonstrating TMCC and now Legacy at Greenberg shows with Steve and Ernie.