BI Platform Support Tool Enhancement Request: append parameter

Hi colleagues,

In SAP Note 1861180 - Customer instructions and best practice for collecting a BI Platform 4.x end to end trace [Video], it says:

Edit bo_trace.ini and change the value for the parameter keep_num to 20 (for Webi workflows, use a keep_num value of 50).  Also update the value for parameter append to false.

But in BIP Support Tool 2.0, the parameter append is set to true by default.

Could you tell me the meaning of parameter append and provide me the best practice for setting this parameter?

Thank you!

Best regards,

Alfred