Indicates that MembersChangedDetailed will be emitted for changes to this group's members in addition to MembersChanged.
Clients can then connect to the former and ignore emission of the latter. This flag's state MUST NOT change over the lifetime of a channel. If it were allowed to change, client bindings would have to always connect to MembersChanged just in case the flag ever went away (and generally be unnecessarily complicated), which would mostly negate the point of having this flag in the first place.