Hi,
We have not yet tested DJI Mini SE, but the app does support similar drones like mini 1 and mini 2 in the new "Free Flight" mission, which takes the images automatically while you drive the drone manually. Images are taken according to the trigger distance you set at the beginning, creating enough overlap to achieve more than sufficient precision.
To answer your second question, the new version now contains the camera settings within the 3Dsurvey pilot app making the general workflow way simpler.
The app also contains a couple of new convenient missions, which however do cost around 5€ a month.