Consider a sandbag as backup with a leash to your safety line. If the stake ever fails, it would slow things down at least. Easy too.
The foils are so easy to self launch, I guess the self landing is a bit of a tradeoff, in that you need to learn some technique.
As for the backstall landings, they work, but you have to commit.
Another idea, depending on your location...If you can, bring a long pole and hammer it into the ground. Backstall in front of front of the pole (I guess a car would work too), then run toward the kite, allowing the kite to wrap around the pole like this:
This pole was already conveniently there, but you get the idea.
(Oh, and yes, this is landed edge down, not back stalled. You can land it that way on snow and let it drift into the centre of the wind window without hurting the kite fabric).