No damage is okay, I know I use it. Basically it doesn't slow down your vehicleafter loads of tries. But it's much more useful with aerial stunting. That way I won't die everytime I crash/scratch so I can just reload the start position (teleport, not loading a save file) and go again. But only scratchless stunts count. It's very easy to tell when someone has modded an aerial stunt. If you see a plane gliding along the floor then it's defo modded. Without the mod the plane would explode the same second.
People make mistakes with tail/landing gears going into the ground. That's because they're mostly not solid and replay shows only vehicle movements, not it's current stats, which sucks. I was making a mod that would hide the landing gear in reps but the work's stopped because my TXD workshop has bugs...