The KV limitations are for specific motor sizes. If you are running a short course size motor, you can definitely run a higher KV rating than a Truggy/8th scale size motor. Used to be easy to say "9 turn motor limit" when RC motors were all the same size. Now they are all over the place and their current demands are as well. Just a KV doesn't tell you the whole story about the esc being capable of handling it.