Is there any way to find out if a specific position is on the navmesh?

so i'm doing stuff with pathing. I'd like to know, is there any quick way to check if a specific location is either on the navmesh, or floating within a certain distance above it (ie, within its horizontal boundaries)

I know i can path to invalid locations, and the path will just stop at the closest point, but i don't want to do that. for one, path calculations often take several frames. I'd like to just drop/ignore orders to invalid locations, instead of going to near them.