1.3 is the highest I would go... I find that a standard microcoil works best for me wicked with rayon...
My go to on a mech would be an ID of 1.8 - 2 mm 1.1 ohms. Don't remember how many wraps because I run my kayfun on a regulated device now..
I make the coil line up with the juice wells so there are no kinks in my wick.