Create a separate text box that is only readable by IIQ administrators to add notes on the Standard Properties or a new tab.
Create another tab named versions to be able to see when someone removed or added a role to the group.
This would help track who’s changing the roles and one would be able to add comments as to why it was changed.
Are you looking to audit the group changes for compliance? Or just to review the changes?
We had a similar use case for admin notes in the past and created a plugin called UI Enhancer Plugin to solve it and several other UI use cases we’ve come across.