Few queries related to streams

I have setup a uni directional streams in testing environment.

It is done for replicating few tables. The replication seems to be working fine. The changes are getting reflected in the destination database.

Is there any way to monitor the replication based on SCN values?

Is there any way to monitor the replication by comparing the no. of messages (captured, applied, enqueued etc.)?

I have refered few documents and found monitoring options only to check for errors, check if the processes (capture, propagation, apply) are up & running.