I have mine on a slider. I have never owned or flown a jet with elevator being used to brake. With that said.
The main thing I see wrong with using the elevator stick is what if your 3 minutes into your flight and all of a sudden your gear (AIR) come down due to loss of air pressure. You have your gear and your brakes on two different setups (should) but the elevator braking is only activated when gear switch is down. But because you see your gear come down you have a (dumb) moment and say "ok, gear is down, Ill setup for a landing." Upon touchdown you go to apply brakes and you got nothing. You quickly flick your gear switch and you try to brake but it runs off the edge of the runway.

I know its a far-fetched scenario but it very well could happen to anybody running an air system.

Just my 2 cents.