So it appears to be the floating point error I noted before.
Utilizing the AutoCAD API (via a zero touch node or Python) to generate a BlockReference.ByCoordinateSystemAtParameter node would be a good idea (this is a common use case as I understand), but that’s a bigger lift than I have time for at the moment.
In the interim you can utilize this graph:
Coordinate system.dyn (239.0 KB)