All are great on their day,
Flag and Matas definitely have more good days in the off season, Oct to May.
All have great teaching centers with safety back up.
You are used to boat launches being centered around Lake Garda, so Flag beach will suit well for that, but I would guess you just need a mornings one to one tuition and encouragement to get back into the swing of things
Give Gunnar a ring who will sort you out with just that, and enjoy the massive sailing area on offer at flag,
Look up Gunnar's details at __ The Boardroom, Fuerteventura, Gunnar kite surfing Pro.