Best practice for running combined reports is to always ensure that all submissions have been received and the project link is closed prior to generation.
During the initial phase of your project if there are a few late completions that you would like to be included in any combined reports, as long as your project and link are both active (Project Status = Active and Assessment Link = Valid) - then delegates will still be able to complete Wraw, and their submissions will be included in any combined report.
You can therefore encourage more submissions, and then re-generate the Team or Leader report as many times as you wish during the initial phase of the project. Each time you generate the report, it will include all submissions to date.
If a retest on the same group of responders is to be carried out later, then best practice is to set up a new project link. It is not advisable that old project links are used, with old submissions deleted to allow new completions.
If an old project link is used and more than 4 months have passed since the initial download of any combined reports AND new submissions have been received to the project, this is classed as a new report and will therefore be chargeable.