Can the stack furnace be altered some with how it snaps to grid? It seems to be really common for people to build it 1 tile away from a wall or building, with the opening for it to be pointing toward the open side, as it aesthetically makes sense.
If having the way it snaps-to-grid altered is untenable could we maybe see about having the bellows rotated 90 degrees, to be on the side? I think this'll help with people having it built improperly.
Normally I'd think this is a very small issue in the grand scheme of things but I've seen three hermitages do this, myself, and a few people in discord.