80% should be fine for stockpiles. The camera being recognized as different models is a bid... odd. I only see one flight in your uploaded flight data and it says 'Mavic 2 Zoom'. Since you are doing such small areas flying slower will always help your accuracy by minimizing motion blur and it helps to keep the images all captured at the same speed.
If you are concerned about the data run a subset of it for free and check the overlap in the Overlap Report. You really want the area you care about to all be dark blue in that report.
When making your measurements use lots of points to define your measurement polygons. 20 points is better than 4. 50 is probably too many.