In SQL Server you can create tables with geometry embedded (point,line, polygon).the geometry can be populated using the STPointFromText ( 'point_tagged_text' , SRID ) function.
We can then create also geometry with Z values parsing X Y Z values in the function.
But it looks tome that there is only the Horizontal CRS that can be defined (SRID , 4326 for ex).
The Vertical CRS (MSL , epsg:5714 for ex) can not be defined in the Microsoft Geometry storage ?
Same for the Query Layer in ArcGIS, only the Horizontal CRS can be defined or extracted ?
Philippe