I should soon be flying an interesting job from outside into a building where a company manufactures large products. The opening is large enough for a truck, so I'm not afraid of that. Ceilings are about 20ft. high. What I need to know is what to expect during the transition from outside/inside. The structure is made of huge steel I beams. Most things inside are metal. The builders said there are problems with GSM signal and wifi inside. I'm in Naza-M mode for IOC, should I flip from GPS into Naza (manual is not set in my settings) or just let it lose GPS and keep going? Should I expect any compass problems? I have a plan B, which is building a small trolley that the Phantom would "pull around", but would be heavy enough to not allow and drifting/flyaway and would not allow more lift than the bungees allow. This would also be nice for small places like inside a house. Anyone happen to know the approx. lift power for full throttle in kg? Oh and there won't be anything that could be damaged in case control is lost. Pretty much just an empty huge production plant.