Works on my .700
The parameters I have already posted allow you to enter Atti by switching from GPS to sport and back to normal, but you will be in Atti.
You cannot get back into normal GPS once switched, until the MP has been restarted, then the process is the same.
This gives you the beauty of always having GPS (normal) when you switch the MP on and the ability to go with to Atti, unfortunately as above you cannot get back to ‘normal’ whilst in flight, although you can get back to sports mode and have all the GPS you need, RTH works as normal in Atti.
However, a little workaround is to turn all the settings down in sports mode so it acts more like GPS, therefore giving you the best of both worlds (i.e Atti and GPS).
Only issue I have found is that the Mavic is a pig in Atti, its too small and light and does not fly as well as a Phantom and the slightest wind affects it.