"the RCA speaker outputs were as silly as the preamp to amp shunts stuck
into the RCA jacks at the factory. "

I would actually like to have a switch on the front panel of an amp to switch the pre out/main in loop rather than their jumpers. Too easy to lose.

And then my buddy got this Marantz, a really nice one, 2325. It has the type of jack where you plug something in and it breaks the connection. I'd much rather have a switch, even if it is on the back and many of them are.

Another thing I noticed about those shunts is ain't none of the MFs ever the same size. I have had a drawerfull of them and still had to make shunts out of 12 gauge wire because none of them fit.