Good discussion Adam2. Would you consider the I99 vs a bigger sail, It seems to me the bigger wing trumps a bigger sail for low wind foiling.
Unfortunately there wasn't a lot of response for the I99 due it being NEW this season; however 7 knots seems to be the low end. Coreadventuresports.got some pretty good foiling videos so I would absolutely trust his stats.
Infinity 99, 7-10 knots, 5.8M, 92Kg, SS Wizard, 125L-79x198, Coreadventuresports
In the video it took him 10 small pumps to fly.
https://youtu.be/5FdHnpp1Hos
Added: I'm sure he's also pumping his foil as the sail pump doesn't look too aggressive.