I have K70's for gravel, they do a far better job than you'd expect, and are good in hard pack too....but doubt you could go very far off road with them....farm tracks and like is all I've done. But the tread design means they are practically bald before getting to the TWI....I still have a couple of mm to the TWI, but will use then for seal only now.
I have 2 sets of wheels and fit the K70's for gravel roads. Tossing up what to fit next, I might try the Pirelli MT43 DOT trials tyres, or something like Full Bore. The Mono has the same size rims front and rear, and I use same size tyres for gravel. I don't reverse a tyre for front use, I don't see the point. The pattern is there for water dispersal, so needs to be the same when on the front. Off road they need to self clean, and a directional pattern self cleans in the same direction front or rear.