I d like to know why it is advised to take off in stabilize instead of loiter mode. Is it a safety issue? Why?
I always take off in stabilize first. It allows you to double check the aircraft is responding properly to the controls. I would imagine if taking off in loiter with a so so gps fix the aircraft could move unexpectedly and at a low altitude. The EKF is supposed to help with this I think but it is safer at low altitude to fly initially in stabilize. Also at low altitude the gps signal can multipath easily and give an inaccurate position. I’ve seen this once when I was landing in loiter. If there is any obstruction around me I will land in stabilize. I flipped a Solo once landing next to my car with a lot of trees around because the aircraft suddenly moved fast to the left as it was landing.
It’s not a matter of being advised it’s what you expect upon throttle up. Once off the ground Stabilize is close to direct control (with attitude stabilization) of the motor output with throttle. Modes that use the Altitude Hold algorithm (Loiter, Althold, PosHold, etc) don’t. Simply read the Wiki for the various flight modes and this will be clear.