Plenty of high performance racing kitefoils fully carbonated. U should see my kiteboard resisting the water and it has been punished well 1 or more directional fiber layers improve directional stiffnes A LOT. Unlike glass Printed parts are just a “model” for laying down the fabrics. I think 1st model of a Bugatti Veyron produced more than half of its weight just from rear (carbon) spoiler at certain speeds and thats almost over a metric tone, if not more.
Also, specific layers of fibers for the same weight as steel and aluminum, give 3-10+ more stiffness. Thats enough for me But, it cracks easier in head on collision but thats not 2 important for this application unless u want to dig out potatoes with it
EDIT: Back in student days, we made mini formula (FSAE), body was from glass and crashbox (nose) was from carbon. We had to satisfy some standards and make it stiff enough for minimum crashing standards. Turned out it was 2 stiff (it cracked up, or better word shattered, half of the glass body and nose remained in 1 piece), so we had to remake the crashbox in glass which finally worked. Max speed was limited to 120 km/h. I hope that gives u some feeling of carbon stifness
@ATRIAY11 maybe u should do front and backwing appart, if maybe later u would like to change angles of attack for a personal favorite stance I never foiled but there is nice amount of “changing angle” talk among some kitefoilers i know.