I will make my question clearer...considering there are sails actually with more power than others (like the ones you mentioned), I would like a sail that have the power to do the same than THOSE POWERFULL actually existing sails with 2 knots less.
Say, if with the actual POWERFULL SAILS for freestyle I can get out and have fun in 14 knots, I would like to see the chance to go freestyling in 12 knots with the same size about 5.8 sail.
I think sounds weird my idea, but I also remember 1998 when saying planning in 7 knots was impossible...after a few years the Formula boards came and wind planning need was reduced in 2 knots just changing the board design. And let me say that the first time I tried the Formula wide boards (85cm at that time) I was planning as with the race small boards but with a different feeling. I am not looking to keep the same exact feeling of an actual freestyle sail with a super powerfull say, just wondering if this is possible and in case is possible...try the feel and check if i prefer that feel having the advantage of sailing with 2 knots less (maybe 10% more days in my 3 hours drive by car spot and maybe 50% more days in my 10 minute drive by car spot ).