I've sailed the Carve 111 (2011) with a 5.5 Retro and a 6.5 Retro and it was very nice.
I see no reason that a 7.5 m2 won't work just as well.
I'll give it a try in a couple of weekends if the conditions are right.
6.3 m2 should be right in the middle of the sweet range on the new Carve 111, and you have the
Go 170 if it's a bit too light to get the Carve going on your 7.5 m2.
Do you have a set of the side fins for your GO 170?