I don't think it's a major problem, tentimes. Yes, the chain can wander from side to side on the axle sprocket, which will give uneven loads on the chain's sideplates, thus shortening its life. However because the sprockets are so close together, I don't think there is much opportunity for torsional oscillation as well.
Thank you for posting this thread, which I will now close. If anyone needs to post to it, just PM a moderator.
