Currently the "progress meter" log message doesn't have the component. e.g. for initial sync:

{"t":{"$date":"xxxZ"},"s":"I","c":"-","id":51773,"ctx":"ReplWriterWorker-0","msg":"progress meter","attr":{"name":"DATABASE.COLLECTION collection clone progress","done":xxxx,"total"xxxxx,"percent":1,"units":"documents copied"}}

It would be nice to specify "INITSYNC" as the component for this message. So it will be much easier to filter the log messages related to initial sync.