for those that experimented with this ...

how does the size size of the back wing affect performance. Namely I have heard a bigger back wing allows for more effective pumping of the foil, given the front wing size variable is kept the same. Anyone found this ?

Also for those that prone surf foil out there how do you keep that damn leg rope wrapping around the mast !! It's driving me nuts !

To help stop leggie getting wrapped while waiting for another wave, you can put it up over your shoulder. I've also seen small floats attached to stop it sinking that can help too.
Most prone foilers I know use a short straight leash & a few using the coiled.

Best place on SeaBze to post about prone is the sup/foil section.

As far as rear wings are concerned from a design stanpoint they provide stability and negative lift to keep the nose from diving.

Too much rear wing will cause too much front foot pressure but will be more stable. Too little rear wing will be less stable with less foot pressure.

For pumping, I've heard that front wing size is the only thing that matters. The effects of rear wing size etc are negligible.

Get a comp thin leash -@ 5 foot long .
Not had a tangle with that yet