I've used the map site to look for seeds with features I find interesting, like meadows completely surrounded by mountains most recently. It would take ages to explore seeds in game looking for a rare feature like that. If you look up boss locations, or even boss stones, trader, crypts, etc. then yeah I would think that's "cheating", although really it's just spoiling the adventure for yourself. Finding the bosses and finding the resources are a pretty large part of the game. I personally find this game gets boring fast if you remove the sense of venturing into the unknown to look for something.