Thank you for your kind words!
Currently, you can enable middle/center point in length/circle measurements using the options.xml file:
https://www.radiantviewer.com/dicom-viewer-manual/options_xml.html
<roi>
<length>
<divide>1</divide> <!-- 1 - a mark is drawn in the middle of the segment -->
</length>
<ellipse>
<center>1</center> <!-- 1 - a mark is drawn in the center of the ellipse -->
</ellipse>
</roi>