I don't know whether it is B.S. or not. I haven't had the chance, or testes to try it yet. But the guy I bought my FX-1 from said that you can trap off the back corner of the wing in 15kts with the chute up and the boat will plane. He said you can get about 4 feet of the leeward hull in the water and thats it.

I'm new to running a chute and today I learned three very valuable lessons about running a spinnaker singlehand while trapezing.
1: Don't drop the spin sheat.
2: Don't drop the tiller. Things turn very hairy very quickly.
3: Don't go too deep when dropping the spinnaker, or be freakish-ly fast about getting it down. Accidental jibe, followed very quickly by almost capsize when it rounds up on the other tack.