I went back today and repeated my flight. I made certain that I had a "fresh" invocation of Go 4. By dynamic (sorry for the error --- I should have said periodically manually updated --- I'm new to the vernacular), I assumed the new landing location would be the last place the HP was registered, and it worked this time. Last time, it went off to lands unknown. I assume if I'm on a boat and I periodically update my HP, it will RTH to the last HP registered. So, I'm OK there. It also works in Follow Me mode as advertised. What I verified today is that unless you make certain that a new Go 4 (not restarted from a previous flight), it will use stale data. I also verified that GPS on my iPad Mini with wi-fi + cell works fine w/o a data link through a SIM card, but will not provide a map. I now need to figure out how to preload maps in DJI Go 4.