Replication with Repmgr + native streaming replication

I have an environment where the old DBA used the repmgr. And now I need to add a second replica to use as a "dump server". But my question is regarding using the native mode of PostgreSQL via stream replication. When I perform base_backup and a second replica is added, can it cause any side effects on repmgr? I've never used repmgr in prod and I just want to make sure that a simple replica can ruin the whole cluster.