We are using HS120D along with a few other smaller drones in a STEM intro to drones. The HS700D is for those a bit more advanced, and of course is FAA registered to fly in US. We hit same problem as with HS120D app, for training in a large indoor gym with ceiling objects at 24ft = 7.1m we can set 7m in the max flight altitude, but it seems to actually be the min listed of 15m. Does this setting work inside a building without GPS access?