In our company we use several datums which come in multiple variants, e.g. Pulkovo, MInna and other West African ones.
We frequently need to set up alternative datum shifts to comply with client requirements for exact positioning (Oil & Gas Industry). These are usually Molodensky or Bursa-Wolfe shifts.
I have done a fair amount of experimenting with the datum creation wizards, and within AutoCAD the shifts seem to work correctly, but I am puzzled that when one views the details of the Datum Transformation from the library, the transformation parameters are not shown as part of the WKT string. Also, presumeably consequently, when data from a drawing with a coordinate system based on this shift is exported to ESRI shapefile format, the transforamtion parametere are not shown in the .prj file.
I do not know whether I have missed a stage in the creation process, or if this this is a bug. It also seems odd that when viewing the details of a user-defined datum, there is no obvious clue as to what the transformation parameters are for that datum, other than finding a transformation with the same code name.
I should be grateful for any explanation of these points.
Is there any chance you can post screenshots of example WKT's that function differently as you describe?
Also, I'm not sure if this applies, but FYI, one of our developers is working on a fix to remove the illustrated parameters:
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