Hi Wasfi,
Access-log format can be made custom to suite customer requirement. The default format used by main log is "bcreportermainv1" which is not editable. What customer can do is to copy the fields from this log format and then create a new format with the fields they need. They can then replace the main log's format with this new format or create a new log with the format. If creating a new log file, you will need configuration or policy to write data to it.
In the log upload settings, the upload can be set to continous to get as real time as possible.