Personally, I think the biggest chance to harm the surface of the shadows is to use a wet or oily brush on them. Also if you grind your brush into the surface to pick up the powder, you're asking for trouble. Wetting your brush to foil the shadow and then double dipping = danger zone.
If you have dry lids, have applied primer with a separate brush and have let it (and your moisturizer, etc.) set well on the eyes and use a gentle stroking motion to pick up the shadow, you could probably get away with a little double dipping here and there. 'Better to avoid DD if possible, but my feeling is it's better to double dip and use a very light touch to get product on your brush, than grind your brush heavily into the surface to be sure you have plenty of powder to avoid the dreaded "Double D".
Then again, I have dry lids and never use a greasy base underneath these shadows (don't like the effect) and don't try and foil them via a wet brush, so I guess I'm a lower risk, lol. My favorite application method is:
1. Let my moisturizer dry completely.
2. Use P & P Vibrancy Eye or a Big Bounce shadow and let it dry completely. (I don't much care for Paint Pots under these - makes them look too heavy for my taste and age.)
3. My favorite brushes for these, in order of love: 226 (control + just the right amount of product), 234 (less control but great for heavier application on lids), 217 (light application all over) and 235 (heavier all over application for light colors). I DON'T like the 239, which I normally use a ton - makes it look cakey. 242 is too stiff for my taste and applies too much product, although it does apply it smoothly, 'just wastefully.
4. I apply a light layer on each eye, let it set for a few moments, then go back to the first eye and add a second layer if necessary - if I do this, I'm either using what's left on the brush or going in with a 219 pencil brush to deepen specific areas, although if any VERY LIGHT double dipping's going to happen, it'll happen here. I do avoid this, though.
2 light layers of shadow, no foiling and having a very dry eyelid surface as a base seem like the most important factors if you want the color to stay all day without creasing. Because this is a powder that has a dry down time, you have to treat it a little more like a cream product, even though it isn't a cream. Blame that new-fangled technology! I'll admit, some colors are a bit easier to deal with if you want them to last perfectly. Dark Dare is the best and Grand Galaxy is the trickiest one, out of the ones I have, since you don't want it to look too dark or too sheer and it's very sparkly on top of it. The more sparkly, the more careful you have to be to make sure it dries down well.