Personally I would try not to use someone elses stand especially the grandsons. I would not to be to keen on someone using my stand. Especially putting a mineral block in the area as well. I am just thinking there has to be enough room there to come up with your own setup. At least if you do use the grandsons try to leave it like you were not there. So I would find another setup and move the block to that location. I would try to avoid issues with the grandson in case he decides to sneak in a quick hunt for his own sanity before the wedding.