Hello Christophe,
Currently, TestComplete does not provide any straightforward way to customize such log messages. To make log messages more explicit, you can use the workarounds you mentioned in your previous message (to use the Log.AppendFolder method or log event handlers).
We have an appropriate suggestion in our database to make such a log message more informative, and your message has increased its rating. Could you please give a bit more detail on the information you want the log messages to include, or give an example of the log messages you need? We could use this information when implementing this functionality.
Thank you.