No. As @pyrate said, you would not have a home point saved if you arm and takeoff in manual.
You may have misread his question: "If I have GPS lock but take off and flight manual mode all time, the return home button still works if i needed or I loose signal?" This is my regular procedure, Get GPS lock and takeoff/land in manual. The lock is what determine home point and has nothing to do with flying in any mode. If controller signal is lost Solo will return to home point regardless of the mode you are in. Easy to check and I have done it. Just get into a hover and turn off the controller. If you takeoff before GPS lock, GPS lock will be obtained shortly after gaining altitude anyway and that will be your home point. If Solo loses GPS and controller signal, Solo will land where it is, not drift.
You are correct. I thought he was talking about *arming* and taking off in manual and never switching GPS mode on. Didn't read it carefully enough.
No, Solo will always obtain a home point as soon as it can. The only difference is whether you wait for it before take off (recommended) or if you are needing to fly from an area with obstructions that are blocking a GPS lock. In those situations, you can take off in manual without a lock and climb to an altitude above obstructions to get a lock. A home point will then be established, albeit above the actual, but at least if RTH is triggered, it will come back above you where you can re-take control or let it land. Remember also that even if the recorded home point is 100' above you, when Solo enters 'Land' mode it will continue descending past that point until it reaches ground (determined by the lack of descent, not altitude).
I'm forced to take off a lot in manual and get up to where I can get GPS and switch to loiter. But I still struggle to accept that a home point would be recorded if I never switched to loiter (Fly). If so that's new for arducopter in the last year. It's kind of a moot point since I almost never engage RTL, but it's nice to know.
Sure, but GPS and flying modes are independent. GPS is always active in the background. It's just whether the mode you are flying in wants to use it or not. And whether you press RTH or it is activated by loss of signal, same mode. It will RTH to the point GPS was first locked. Easy to test; take off in manual and hover for a minute then fly around close by for a few minutes. Then hit the RTH button and it will show you where it acquired. I don't remember it being different in APM 2.6 or Pixhawk, but could be mistaken. From the Arducopter RTL WiKI..
