The coordinate system of the image is UTM + scales and offsets designed so that the lower left corner of the lower left pixel is at 0, 0, the lower left corner of the next pixel to the right is at 1, 0, etc. You can see the scales and offsets applied to UTM in the coordinate system dialog, in the metrics section at the bottom.
If you copy the coordinate system of the image to the drawing, the coordinate system of the drawing becomes the same, with 0, 0 being where the lower left corner of the lower left pixel of the image is, etc. It's not just UTM, zone X, it's UTM, zone X + adjustments. If you want to see coordinates in UTM, zone X, without adjustments, you should project to the coordinate system which does not have those adjustments. One way to do this is to edit the coordinate system of the drawing, edit metrics and set local scales to 1, 1 and local offsets to 0, 0 (all in meters). Alternatively, you can do this dynamically in a query. I altered the 'TileToValues Project to UTM Drawing' in the attached file to do the latter.
The x2 value returned by the CoordConvertPoint call can, of course, be split into X and Y components. To do this, use VectorValue. I altered both the 'TileToValues Project to UTM Drawing' and the 'TileToValues Project to Geo Drawing' queries to do this during SELECT INTO.
A projection can be defined as a value, absolutely. Eg:
VALUE @target NVARCHAR = ComponentCoordSystemAutoXY([component]);
VALUE @target NVARCHAR = 'EPSG:3857';
New file attached.