The restrictions they have now are pretty liveable. You can fly over
the north part of it, and across it (in one place) above some
altititude. High jets and such aren't restricted. Its just the
helicopter and airplane tour operators that can fly low. And there
aren't that many of those. I say leave it the way it is...

If you want to fly IN a sandstone canyon there are some north of the
Grand Canyon with no restrictions, you can even land in the canyon in a
couple of places. Its really quite good!