Always slightly loathe to put my head above the parapet in such matters, but, here's my 2 Pennorth.
On the MacCann, I use all 8 fingers...(4 on each side) and my right hand thumb deals with the air button....!
So, 9 out of 10 digits is almost a full house!!
As for playing fast, Have just listened to an old recording of me and Nigel Chippindale playing the Belfast Hornpipe. Me on Duet, Him on Piccolo Anglo.....Sounds pretty fast to me!!
Not sure if I could do it now though!!!