No builtin method.
Haven’t tried examining the flightplan saved files at all, so most of the below is pure speculation;
Thinking of how you might do this, the planner uses a much smaller number of waypoints to make up it’s line, you’re probably looking at less than 100 for most plans I’d bet.
The flight data on the other hand has likely got around one for every second or so of flight, average flights having a track made of hundreds or thousands of points.
There’s no easy way to do it, right now that I know of, and it wouldn’t be a 1:1 conversion, but you could probably get it to work just taking every tenth or 50th datapoint to get something kinda resembling what you need, and a proper algorithm to remove extra points more effectively wouldn’t be much more complicated.
The problem would be getting that file back into freeflight to load it in flight plan. On IOS anyway, there isn’t an easy way to access those files directly.
perhaps jailbreaking would be needed to access the store of files? I’m not actually sure about that.
Also, I bet altitude and position are in the data log, but nothing about the camera’s angle, or the other settings you set in flight plan - you’d need to fill those in when you opened the file. Things like flying sideways, zooming or using a dronie type thing to focus on a point while circling wouldn’t come out of the gps log data.
The more I think about it the more difficult it seems, especially comparing it to just starting out with flightplan to get repeatable flights.
Maybe more useful would be an option to view previous flights in flight plan.