Hi K,
I have just spent hours trying to do something similar (but different) and have got it to work. I thought I'd share it with you in the hope it may work for you. I'm sure a lot of MS users reading this will think this is obvious or have a better way. I would be very happy to hear from those users.
Your MS job has the Reference Settings set as "Local Co-ordinates" but you later find out your data (including Marker data) is actually on a known Coordinate System and you just want to change the Coordinate System setting of your job to the correct CRS in the Reference Settings. So, you are not actually shifting the data in space, only re-assigning the data to the correct CRS name in MS -
note - this assumes you have your markers in a coordinate file, e.g. csv or txt format -
1. Your MS job is currently defined as "local coordinates" in the Reference Settings.
2. Using the "Import Reference" command - Re-import your markers (using the same csv or txt file you originally used to import your markers) - When the "Import csv" dialogue box opens, change the "Coordinate System" from Local Coordinates to the defined CRS you need. In the example I have attached I am going from Local Coordinates to MGA 2020 (EPSG 7856), click OK and import the data.
3. Under the Reference Settings the "Coordinate System" should now be showing the CRS you want (not Local Coordinates). But in the Model viewer your data should not have moved.
4. In the Reference Tab / "View Source" list - your markers should have the correct Labels (e.g. E,N,Altitude or Lat,Long not XYZ)
5. The data should be in exactly the same place but, if needed, click the "Update Transform" button
Kind Regards,
Ben