I notice in the changes.txt file for 5.2.3 mentions "georeferencing data added to pdf maps" Is this intended to mean that the output co-ordinate system can be printed in the legend, or something more sophisticated?

It adds some additional information to pdf file which can be later processed by xtherion (Help -> Calibrate bitmap) to create a bitmap image + ozi explorer-compatible *.map calibration file.

Printing the output co-ordinate system in legends generally and the 'caves list' would be useful (their common names and or their 'numerical' name)

Indeed, it should be added. Martin