There are already a number of large items in the game that may be crafted and placed in the world. When they have a collision region that is more than 1 tile wide and/or 1 tile deep, the hearthling who places it can wind up on top of the item after it is placed. This is pretty silly.
From what I can see on the modding side, you cannot define a “destination” tag for the ghost of the item, so the adjacency region for a placed item is always the four tiles directly adjacent to the origin of the model. I suggest that the game should construct the adjacency zones based on the shape of the items collision region (which can’t be defined in the ghost.json currently). With that, your hearthlings will be able to place any item and stay on the ground afterwards.