It sounds like a good idea to me--instead of mangling the sound with a tone knob (most of the sounds between 10 and 0 don't work for me), use different capacitors...I like it, but most of the time, I use my basses/amps on just one setting and I don't switch around a lot.
So, I love the idea, but how well would one work for a one trick pony like me? Often things like that tend to be "jack of all trades, master of none". However, that push/pull bypass sounds like a great idea. I might have to just give one a try...