It's possible to have a side wall repaired depending on how large of a hole and if the cost of shipping to have it repaired is worth it.
I've had two of my Krawlers repaired When I put a 1-2" gouge/slash on the middle of the side wall. They shipped it back to the BFG factory to cut around the hole, then poured new rubber to refill it. When I got the tires back, I could barely tell where they refilled it. The cost of shipping was $65 + 25 to fix.
The third tire that I slashed, the hole was closer to the lip, and they refused to refill it and didn't charge me for shipping.