Bert, I was thinking CY when I put up those numbers. 1% Ischia is probably more like 0.01% ADY - again this conversion ratio is for a room temp fermentation.
The number in your formula is 32X that, but I don't think it is an unreasonable place to start. I might go a little lower. I think I used .3%ADY for 17 hours cold+4 hours RT when I tested the MPO.