The reason for this suggestion is that currently you only have an option of showing just one banner (plus staff banner) or all banners. You can't just show, say 2 banners, when a user is in multiple groups.
On my forum the current set-up is that full members display a Senior Citizen banner. We also use the Trophy User Titles and some members can also use Custom Titles. In addition, all members are added to up to 3 additional groups (Level 1, Level 2 and Level 3) with increasing privileges depending on how active they are.
What I want to achieve is this:
This would be achieved by making the Senior Citizen banner non-stackable and the Level 1, Level 2 and Level 3 banners stackable.
Currently I can only achieve these (the first with banners stackable and the second with banners non-stackable)
As I said, we use Trophy User Titles/Custom Titles so can't use the option in user groups for this. Also the user group promotions mean that users are automatically added to groups with increasing functionality so, for example, removing a user from the Level 1 and Level 2 groups and then adding to Level 3 group isn't a possibility as user group promotions don't work this way.