Ah man.... :(
Tim, you better hope Steve Stevens doesn't see this thread or you might be doing a Rebel Yell for one of his flamenco guitars. :P
Sadly nylon strung guitars lack the one thing needed to make a magnetic pickup like a BKP work : steel strings!!
It is when a steel string or the steel core of a wound string cuts the magnetic flux field from the magnet contained within a pickup that a voltage is induced in the coils wrapping the magnet- basic principles of a magnetic pickup
I have
cringed when seeing ignorant salesmen in guitar shops selling a soundhole pickup to a spanish/classical guitar owner.
It won't work - the only options are microphone or Piezo type pickups