Yeah I mean, let's imagine you do a 50 meter run-up. Obviously you won't be accelerating 50 meters (unless, maybe, if you're an elite long jumper or something

), but all these contacts that add up have a tendency to tire you, and it will take "more" to be able to stabilize yourself after all those ground contacts and still jump well.
So I'm giving you a big exaggeration here, that would be unsafe if you were to maximally jump after such a run-up, but if you go overboard just a bit it might be a good idea.
Say you can only accelerate well and plant to the best of your ability in 5 steps. You could and should use 7 steps every now and then, only to make your body try to adapt, over time, to some additional stimulus.
I've said the same thing about a higher box for depth jumps than your optimal box in a post a few days ago. It's just that you don't want to go overboard with it.
If your best depth jump comes off a 20 inch box, maybe try a 22 inch box (put a small plate on the box or whatever stable, small thing you can find) every now and then to overload the system a bit more than what it's "optimally" accustomed to. I guess this would be similar to overspeed sprinting or something, or to an eccentric supramaximal squat or something like that.