I have to thank you for this idea!
I found out, I really like the idea of adding the recording disambiguation to the track titles, because it’s information otherwise not available at all. But (for me) it should be added in case of live recordings only, to avoid comments like “this is the short version without telephone ringing” being added to the track title. Therefore I made a little change:
$if($startswith(%_recordingcomment%,live),
$if($rsearch(%title%,%_recordingcomment%),,$set(title,%title% \(%_recordingcomment%\))))
… if there is no _recordingcomment or it does not start with “live”, an empty string will be returned and nothing will be done.
EDIT: substr() removed from script