Reported by Marek:
heliographic coordinates of the center of the solar disc correspond to satellite position,
and in the case of Stereo A and B satellites change continuously with time. It was so in version 2.3.3. Now the coordinates (displayed in the lover right corner of the image) are the same as for Earth’s view i.e. longitude of the center of the solar disc has always value 0 for both stereo A and B. Algorithm from version 2.3.3 is more useful if you want to track the movement of individual solar structures.

Reported by Marek: