I've read this whole thread and made notes. I was ready to order, but ran into an unplanned expense. I've never heard the Yamiko IRL, but would love to this summer when I'm in Dallas! The answer is "yes" people have gone from one sensor to 2 and have gone on about it.
BUT, I know you and I remember you telling me in your practice space that you were ready to not have all of "this stuff" on your gigs. It seems to me, the rabbit hole with Yamahiko is this:
It's the best piezo pickup ever, bar none! But, you can add the 2nd sensor, but wait, you can split the signal and reverse the phase and send each signal to your Felix and WAIT, what you really need to do is blend it with a mic and bounce the whole thing off of the International Space Station and then bring the signal back into your powered speaker, which should be at a 39.2 degree axis to a braided ficus tree that you bring with you to every gig...
If it's really the best piezo pickup of all times, which I don't doubt, then I think YOU PERSONALLY should resist chasing better.

But, maybe I'm being presumptuous and you've been gigging with it. My plan was single element into my amp, focus on playing better.