What I don't like about it is, the more relaxed the landing requirements are, the lazier people get. It's not really a major thing, but it doesn't look right to have people just bellylanding to get down.
Maybe a possibility would be to have some kind of point value assigned to the stuff that's missing from your vehicle, and based on that have either tighter or more relaxed requirements for landing.
So for example, say it was a system something like this:
Ailerons 4 points each.
Engine 8 points, or 4 points each for dual engines, 2 each for quad engines.
Rudder 4 points.
Elevator/hstab 6 points per side.
PW 6 points.
Gear 6 points.
If you've got less than 6 points of damage, gear down and on concrete would be required for a safe landing. 6 to 12 points, anywhere on concrete gear up or down is fine. If you've got accumulated damage over 12, anywhere within the perimeter is fine.
This is just a barely formed, off the top of my head thought, but I think it'd be a better compromise than what they have.
The line they've drawn isn't too terrible, although the babying it home and losing it because you're a foot off the runway does hurt.
Wiley.