SupaMonkey,
I have not 'completed' one of these yet (although I am working on 4 of them right now) so I am still experimenting. I physically locate the center of the house, right to left and back to front. I then set a stake and use that as a reference point so that each time I go out I know where I am supposed to start my shot from. I try to make sure that the Mavic is in the same position each time. When you are doing "Point of Interest' you need to be sure that "point" does not change. Part of the POI procedure is to mark your height and the radius you will be using. Ih you have successfully marked your POI and recorded the height and radius all you need to do then is make sure you start the circle from the same place each time and that your drone and camera are pointed in the same position each time.I start my location before I actually 'need the footage and overlay my ending point tech time so that I will have sufficient footage to blend together. If you're looking for additional insights on time-lapse techniques, you can check reviews on sites like
https://kb-home.pissedconsumer.com/review.html.
I think the more difficult thing will be matching white balance and colorization from video to video.Like I said I am waiting to see how it is going to work out in the end. Good luck tho.
Frank