Akka Persistence Cassandra - High RU/s on tag_views table

I’m currently using Akka Persistence w/ the Datastax Cassandra plugin against CosmosDB. I also leverage Akka Persistence Query to create a projection from a Cassandra Read Journal. (see below)

The thing is, running our projections with no new events coming in, I’m seeing ~186 RU/s (approximately, requests/second) against our DB on the akka.tag_views table when the projection is running. I’m running 12 instances of a projection. My tags are “aggregate-slice-{1,12}” naturally. This load seems incredibly high and it feels like the DB is extremely busy. How do I make things more reasonable?

Edit: I’ve narrowed the high load down to query.refresh-interval and backtrack.interval. Why is the default backtrack interval 1 second? That seems pretty frequent in conjunction with polling queries every 2 seconds.

cassandra {
  events-by-tag {
    bucket-size = "Day"
    eventual-consistency-delay = 200ms # i've tinkered with this from 200ms to 5s
    flush-interval = 50ms
    pubsub-notification = on
    first-time-bucket = "20201102T00:00"
    gc-grace-seconds = 0
    back-track {
       interval = 1s
       long-interval = 120s
    }
  }

  query {
    refresh-interval = 2s
  }
    SourceProvider<Offset, EventEnvelope<Message>> sourceProvider = EventSourcedProvider
        .eventsByTag(
            system,
            CassandraReadJournal.Identifier(),
            tag
        );

    return CassandraProjection.atLeastOnce(
        ProjectionId.of(PROJECTION_NAME, tag),
        sourceProvider,
        new ProjectionHandler(system, tag, producer)
    );