George,
Please don’t spin your wheels with the vibrato effect edit. Just got a reply from Bad Mister on a Yamaha forum that what I’m trying to do with the vibrato effect cannot be done (on the MX-61).
Thanks for the hand… still testing and may be back later.
Ol’ Will

Hi Will, I was just going to reply and realised there was another page of messages.  I have had a play and can’t get rid of the vibrato for the flute.  I suspect that it is in the original waveform definition. Other pipes such as the Irish pipe don’t have it though.  It sounds like a very nice flute sound though especially the “chiff” at the start of the note.  Bad Mister is very knowledgeable and helpful in my experience.