These sprinkler permits are kind of telling because they only need to add additional sprinklers in rooms that will have ceilings or are covered in some way, preventing the building's existing fire suppression system from being effective in those scenes. The house in SS25 definitely has most new sprinklers going in, at 14. I believe that's rumored to be where Stranger Things is so it looks like we'll be getting a lot of covered scenes in there - I'd imagine the tunnels from season 2 will play a big part, hopefully the arcade, and maybe a few Starcourt Mall scenes too!