I am not a lawyer, and this is not legal advice.
Many original synth patches are under copyright, and are specifically forbidden to be copied/recorded to create other musical instruments. They may be recorded as part of a musical work, but not as a sound library.
The last thing we want to do is to get PianoBook in hot water over copyrights and potentially shut down.
So, do you know the origins of the synth patches? did you create them, or were they created by Kawai or a third party?