Hi mate say you fly in your back yard you calibrate it , then it you go to the end of the road you should calibrate because it you hit return home it will return to your backyard which could put any one out in your yard the danger of the quad coming down
Also if your a lot more of a distance away you stand the chance of loosing the quad if it goes on to return home mode as it will go to its last known calibration point which was your yard which it may not have enough battery
Um. No.
Calibrate it when you first set it up, then don't worry about it. If you travel a far distance, like hundreds of miles, calibrate it again before you fly. The RTH point is set as soon as it has stable GPS, so holtneil's narrative won't happen. RTH is not set by calibration.