1-Position your foil according to this:
www.blueplanetsurf.com/blogs/news/foil-board-setup-tips-board-foil-foil-placement-fo/2-Wing the board without straps a few sessions.Note where your feet feel comfy.Float&Foil foot position should be the same,specially important is the front foot.Back foot can move a lot easier.
3-Put footstraps in that position.
If inserts do not match DIY or have a shaper or repair guy put new inserts.