I am often dissapointed when see new intelligent flight modes on the new DJI models. For example Helix for the Spark and now Boomerang for the Mavic Air, both shots are possible to pull off manually but I usually end up with some slight unintended movement that ruins the video. I've been messing with Point of Interest mode and I think both the Helix and Boomerang modes can be "simulated" by modulating the altitude and radius. Check out these 2 shots I recently got using the POI mode.
On this shot I reduced the altitude and radius at the same time
On this shot I increased altitude and raduis until half way around the circle then reversed the movement to decend and decrease the radius.