Hello, again. So, I've went again to both stores, and if we take the trolleys used in so-called "hypermarkets" as reference, and classify these trolleys as "big"... In the first store (https://www.openstreetmap.org/way/359658634) there are "small" size trolleys available, and in the second store (https://www.openstreetmap.org/node/3647434258) there are both "small" and "medium" size trolleys available. And, looking at the size of both stores, I would call them supermarkets (and not convenience stores). So yes, I consider the tag "shop=supermarket" more correct than the alternative "shop=convenience".