I’ve just done the same for mine, having crashed twice snapping the front suspension holder in one crash & again in the other, adding the servo saver as well. I ordered quite a few parts to stock up on, front arms, tower, servo saver, Ackerman etc as, like you say, they are cheap enough. I thought £30 on stocking up would future proof any damage and save waiting for postage.
Today, the servo gave in so contacted MS asking advice about a replacement & could they do anything warranty wise as it’s only a month old. They must have checked my ordering history as they said it must have had an impact lol
with the amount of spares I’ve bought, they understandably think I’ve properly totalled it ha ha. Can’t blame them to be fair lol. Anyway, I ordered a new one, a 15 kg metal extronix