My CR 9.0 is the 2006 model, As Severne masts never reached our coasts until last week, by two years we were rigging CR sails with another brands (lots of experiments, we are like a tuning dream team of the third world !!!)
The CR 9.0 is a great sail as any 2006 model (you can see some PWA racerīs photos with certain sizes of these sails instead of CR2 at the 2007 season ) despite the lack of upper leech reinforcement, something that Severene Fixed on CR2 and CR3 (2008) and I rig it with a North 490 mast that fitted perfectly.
I saw some CR2 and as you say seems to be so flat, the 2008 CR have Deeper profiles (I have a 7.7 and 6.7 and work nice). the solution could be to rig the sail with a mast with a softer tip -the tip extension is ideal for that- this will force the sail to open the upper leech and keeps the lower profile deeper with less luff tension (better profile + safer for the sail)
I hope this can help you.
To Hookipa 18:
I tried my 7.7 with the IS133 and seems that is too small in order to get good performace (suitable but not performer). I guess that the tail/fin size relation limits the sail size as Formula do for racing performance. I tried with a DB SL246" and the stock Drake 52 fins.
My opinion is that with a well tuned 9.0 rig you can handle almost the whole "fun" wind range for that board and your weight (11-17 knots).
Best regards and good winds for the weekend