I took Marlon to surf Friday evening. I brought the foilboard again (I really want to nail this thing), and from the Thursday experience I thought I'd jam the foil the complete opposite way.
With the foil pedestal all the way back, there was a lot less lift. The rides were way more stable, but on a couple I didn't even lift above the water. On the ride I did have, I could feel there was a lot less "full throttle bucking" and more of a glide. I need to get back out with the foil mid box - I have a good feeling about this!
One more note in general - the positioning of the pedestal should be a function of the lift generating capability of the wings - more lift from the wings for a given speed of travel (and payload weight), the further back you can place the wings. Keeping the sport static (windsurf foiling, prone foiling), speed of travel constant, and rider weight the same - the smaller the foil wing the further forward you can mount it.
Honestly - 20+ years ago when I first learned to windsurf, I was enthralled by it because of the sail and the adjustments you could make to get more or less out of it. I was frustrated because the wind was mostly just below the strength I needed to get out and sail - and then kiting came along and opened up that wind. Kiting is still really fun - but it doesn't have that element of balancing of forces - you just measure the wind and put up the kite you think you can hold down. Foiling is giving me back the goal of being able to understand adjustments and now there is no wind range threshold to meet. I'm hooked!