I think it would be a neat feature to allow Udon to have some interaction with groups.
For example, you could have a user click a button in your map, and be sent a group invite or be brought to a group's page. This would be easier than having a sign with your group's join link/code.
It would also be interesting to allow Udon to check if a player is a member/staff of a specific group. (However, this might be somewhat exploitable? Could lead to a 'join X group to enter the world/room' type thing.)
Another idea could be a button to give the player a role in a specific group, such as a "completionist" role for completing a long map? (For security, maybe the world owner would need to be a staff or owner of the group?)
All of these are just ideas, but I think it would be really interesting to see some kind of Udon and Group interaction.