DJI SDK only allows 2 sec for JPEG and 5 sec for RAW on Mavic pro (and other drones), but the drone is capable of a much higher rate (provided a fast enough sd card). JPEG quality is very bad, so RAW is preferred, and 5 sec is very limiting.
Implementing a custom intervalometer would be very useful.
Litchi is aware of the DJI SDK limitations and have implemented a custom intervalometer, and it works very well. I tested the Mavic PRO and it has no issues with 2 sec interval for RAW.
It would be a boon for photogrammetry and also simple to implement.