I tried it today. I put a 4 minute mission, up to 2 miles away and back, into Litchi and flew my Phantom 4 on the mission. At about 2000 feet away, hills and trees between us, it lost signal. It continued on its mission and completed it. So the answer is that on a Litchi mission, if the P4 loses signal, it does not return to home upon loss of signal but continues on its mission. I do have RTH on loss of signal set but a Litchi mission overrides that.If you lose signal (lose the connection to the aircraft) then you can issue no commands and receive no feedback (or one or both may be unreliable if signal is marginal.) But if RTH is set correctly the aircraft will RTH upon loss of signal and you will probably regain the link on the way back, and can then cancel RTH if desired.