Rick. Interesting, I've been collecting capos since 1972, and you're right, I'm not as old as you, and likely not as wise...maybe I can get some kinda disability pension for that... I like your idea alot. It considers the break angle of the string over the fret at which the capo sits, much like we consider the break angle of the string over the saddle and nut.
My solution was to cut fine slits in a Schubb capo rubber so that the pressure from the lower pitched string didn't prevent the capo from holding the octave string securely. The result is that every string can then compress the rubber only where it contacts without affecting the neighbouring string. This is less an issue now that I have a good 12 string (Beneteau) but it still works. This is sometimes a problem with my Baritone too, particularly when I use a .066 for the low string, not so bad on the .059. I'd love another 12, but there's that domestic harmony thing to consider.
The other thing which works for me is to use a softer rubber, like hydraulic hose, than that which is provided by the capo manufacturers. This will compress more pliably (is that a word?) and prevent excessive pitch sharpening. This is that break angle thing at work again.
I like the Golden Gate capo too, but I use mine mostly as the prototype for making other capos for virtual tunings. The only place I've ever seen them is in the Elderley catalogue. I should buy another, though I think the rubber they come with sucks so I replace it.
I once had a satchelfull of (mostly Schubb and Kyser and Dunlop)capos swiped at a festival, about $300 worth I guess, and it took me ages to replace them all to my satisfaction. Whoever got them likely scratched their pointed head for a while. I hope they're using them creatively.
I've written about capos alot on the Acoustic Guitar Magazine discussion forum under my real name, Mike Crocker, so sorry if I'm repeating myself, I can never recall what I've written where.