On a single unbounded (CPU + mem) Debezium running on a VM extracting Postgres, I was able to clock in about 7-10m/hr. You could increase the # of tasks, but then it'll hinder your DB perf. Also, this is on your primary DB.

We found it far more efficient and less risky to do CDC streaming and snapshotting w/o read lock in parallel to two different topics. Once snapshot is done and drained, we then move to drain the CDC topic.