This is collected already at Session-level as I showed above. So you could get this based on the proposal to add the ability to aggregate these Session metrics into named buckets.

Your question brings to mind that it might be nice to allow that to be multi-valued (aggregate to multiple named buckets for a given Session):

session.publishStatsUnder( "territoryMapUpdate" );
session.publishStatsUnder( "territoryMapUpdate", "procedureCalls" );