Surprised nobody has mentioned this yet...offline planned waypoints for photogrammetry.
Your own FC gives you huge advantage over the competition who are struggling with DJIs inconsistent SDK implementations. Yours could be like butter with large number of waypoints...hopefully.
1. Overlap and parallel track calculation based on height and custom polygon size/shape. (like original DJI GS s/w without the clunk)
2. Adaptive bank turns.
3. Super fast travel to first waypoints and fast return to home when finished.
3. Single mission with multiple flights with a battery change for large areas.
4. Optional automatic oblique images to build 3D models for good representation of vertical surfaces.
5. Cloud processing is not a priority for me as there is very limited control of the post processing for serious mapping. Better left to dedicated software e.g Photoscan Pro, ImageJ for NDVI etc.
The all in one apps have their market, DD, Pix4D, MME. What is needed is a multi optioned dedicated flight only function for mapping... all we need is good flight programming.