My ++ is NOT switchable. But I can adjust the treble volume and gain down to where the + lives but not vice versa. I do agree with everything you said about boosting a +. Just isn’t the same.
I picked up the RI. Previously owned a Dual and Single. They were tubby and shitty. The Dual had to be a G. The RI is waaaaay better sounding than those amps FWIW.