I'm told that a Larry Neal in Texas had a BRS fitted onto a tandem Air-Command at some point (personally I'm not sure I'd fly an Air Command with a chute!, and certainly not without). I know no more than that, but it might be worth seeing if you can track him down.
I disagree with you about descending onto the tail - the whole aircraft structure is designed to absorb loads when it comes down on the maingear, and redesigning other parts for the same purpose is just going to add weight and complexity for no good reason.
G