Yes, I did try that, but I can't get it to work. If I put an Invert Modifier on the Link, the link doesn't invert its behavior (ie, Off doesn't become On and vice versa). And if I put an Invert Modifier on the next level down, the control also doesn't function at all.
My guess is that Invert is multiplying the input cc by -1 (I'm not sure how to see the actual output, so, who knows?) Since my MIDI control button is outputting 0 and 127, simply multiplying by -1 would result in -127 and 0. But what I need is 127 and 0. So I guess I really need an expression like: [ (-1 * input) +127 ]. Do we have full expressions in SMode?
-jm