It is mentioned in several posts that one can align two geo-referenced components by setting “Lock pose for continue” to True.
However, that does not work for me at all or I am missing something.
Scenario:
Project A with many cameras aligned in one component, geo-referenced by laserscan.
Export some cameras from a smaller area to Registration B and import it in a new project C.
Need some more cameras because there is a gap in coverage for texture.
Go back to project A, export few cameras to Registration D and import them in C.
This is necessary - importing all required cameras from project A is NOT an option.
Now as I understand it I just have to select the above mentioned for all images and it should work.
However, I end up with one component but the geo-referencing is lost and the object is completely randomly placed and rotated.
I checked with CPs - it’s completely off.
Then I tried it with Pose groups - same result only different arbitrary position.
Changing “Absolute pose” from Unknown to Position to Position and orientation and finally Locked also did not help.
Same for “Merge components only” and “Merge georeferenced components” - in all imaginable combinations.
Only the startbursts look different each time… 
What am I not getting ???