It does nothing to change the fact that one would have to manually untag the vlan for any specific port on a switch
Untag the port and tag the bridge, I guess?
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Setting bridge as tagged/untagged under /interface/bridge/vlan doesn’t affect functionality of bridge the switch-like entity, it affects the bridge CPU-facing bridge port (check this excellent explanation of different bridge personalities).
The above has the same effect as setting VID/PVID on any other (physical) bridge port. So per-se it doesn’t affect the way MVRP operates.