There is currently a bug in the game when you put a blueprint in the ground and it can not be accessed.  There is no way of removing the hammer icon and its an eye sore.  What if there was a timer on blueprints if you dont do anything in two or three days then the blueprint just disappears along with the hammer icon?   See attached photo as example of this bug.  

https://gyazo.com/33c76854d7ef3bc195f74b9b5841e5c9

that's bugged me also.  got my vote to include this.

This should envelop other things too like materials left behind (e.g. grass planks used or in the stack element, plant fiber, dropped materials).   They should "age out" with something acceptable like 2 "game days" if you haven't touched the item.