So, no need to define it anywhere else! OK, good to know.
So, which of the 2 possible options is the correct one? The copy from the guest network or the copy from link? Aka, should I create the bridge or not?
(The target is to extend this SSID to my other AP later)

And to clarify. The br-lan has a device named as such. But the br-guest doesn’t that’s why I am confused. Why is it needed for br-lan but not for the br-guest?