Do I understand this correctly: without manually designating a root bridge, the root bridge would be selected from switches that include the highest vlan id, as this would increase the extended id value within the switch(es) in which that vlan exists...

I still cannot find my answer to this: the System ID Extension has values from 1 to 2048. The default is 1. I'm assuming from default VLAN 1. But how can the System ID Extension even change from 1 to another value? I don't see any documentation where...