We actually never designed a function for that specific job.
However, you can still do it by exploiting a module designed for an other purpose: the change detection one. https://sarproz.com/manual/change_detect.html
Load the single master images graph (star), then open the module, select “multiple pairs”, and in “data export” choose “input data” from the menu. Then press “go”. The software will geocode all images amplitude in a row (make sure you do not have the automatic Google Earth call or GE will be opened after every geocoding process).
Reflectivity Map = average of all images amplitude. That’s a single map, you can geocode it via “extended data export”.