I have used tapered strings (out of necessity, I was out of Slinkys and the B broke) and there isn't a problem with the EBMM bridge.
Tapered strings are a problem all to themselves, though. That is what I think, anyway.
Hmm, that is strange, isn't it? Wonder if Scott'd be so kind as to tell us about it?
Personally, I can't see any reason why EB bridges would function less than perfect with tapered strings?