i think power is a more useful quantity to find than force. force in the c-loop is useless as it is not comparible to anything else. if you calculate the power that the kite is generating at least you can compare it to something such as a small outboard etc.
- also that calculation was average powerover the 2.5 seconds. peak power may be significantly higher than this as the power would reduce as you slow the upward motion towards the top of the jump.