Somewhere in the unity forum is a post by bgolus (and only a few posts back in the thread bruno posted) in which he explains exactly what bruno is proposing. You calculate ddx and ddy of the regular uvs and use a different sampling function tex2dgrad() instead of tex2d() (which isn’t a node in shadergraph for some reason, but you can simply use it in a custom function node).
Nevertheless hiding it the way you did obviously works as well if your texture allows it 