It’s not surprising there isn’t much information because noone that I have seen or heard is doing anything like this. Most people are using GCP’s for ultimate accuracy and the fact is that there are allot of cases that people just want decent accuracy and all the maps in the series to align. With processing of images only with native drone GPS you will see image adjustments up to 12-15ft and they are relative only to that flight. The machine tries to fix it as best as it can, but that is just the limitation. Pulling information from Google Earth is another step that you can take up front to create GCP’s before you ever fly if there are enough permanent objects on the ground to locate. It will get you within 2m (6ft) easy and depending on the update of the Google Map you can get down to 1m (3ft) on the RMSE.
Here is the other similar thread.
…and some support docs.
Uploading Manually
https://support.dronedeploy.com/docs/how-to-process-datasets#uploading-images-to-a-new-map
Processing GCP’s