Left-footed player gets put on the left every week

Yes, I would deliberately give him other experiences. Being left-footed is useful, but it should not become his position. Central roles will give him different pressure and scanning pictures. Playing on the right can encourage receiving inside, combining on a different angle and using the outside of the foot. He does not need equal minutes everywhere. By U11 it is reasonable for players to have areas they know well, but I would still avoid one physical trait deciding their football education. I would explain why you are moving him so it does not feel like being played out of position for no reason. The question is not “where does a left-footer belong?” It is “what experiences will help this player become more adaptable?”