Currently if a quiz is linked to the Gradebook, and the "Last" option is enabled to send the latest grade to the gradebook (as opposed to "Highest"), if the grade achieved on new attempts is the same as the grade already recorded in the gradebook, the record is not updated. This presents a problem in certain situations where the quiz is a requirement to obtain certification, because the date of completion is not updated in the Gradebook. The result is that users retaking the quiz don't receive an updated certificate with a new expiry date.
There is a related sakai.property (gradebook.externalAssessments.updateSameScore), which when set to true forces the Gradebook record to be updated even if the scores are the same. This resolves the issue described above, but it may not be the desired behaviour globally.
In consultation with Longsight, it was determined that new behaviour in edu-services should be developed to allow a site property of the same name to override the functionality defined by the global sakai.property. In this way, institutions with a low number of sites requiring this behaviour could use the site property, while institutions with many sites requiring this behaviour could elect to use the global sakai.property.