Anyone been rejected from app store for not having x4 assets?

I'm trying to find out if I can get away with just including x3 or even x2 assets in my app and not get rejected from the app store.
I've looked through the dev guidance, but can't find a definitive answer. Anyone got any experience?

I'm pretty sure that I read this was impossible.

What do you think is impossible? To get rejected for having elements that are scaled to fit, or to not get rejected for this?

I should have been more clear, I'll be including x4 assets, but on certain devices that don't have enough ram to ensure the app will run smoothly, I'll force scaling of lower res assets and o fill the screen.

I usually include only x1 and x2  assets (for pixel art game only x1) and always get approved.
As long as graphics look smooth and not blurry I don't see why they should reject.

ShimieGames, fantastic for your confirmation. I'm using x3 graphics scaled and no one can tell the difference.

If they reject me, I'm just going to keep elements of the background x4 and scale everything else.

Same here, I design at 1024x768 for iPad and exclude anything but 1x to keep the upload size reasonable. Graphics look good when  run as Stretch to fit.
Never rejected because of this.

Thanks, gplar, I've been working for so long on my game, that when I hit my memory problem I had a bit of a panic. but it sounds like dropping the res of most of the assets is the solution.