N-Way multi-master configuration

We are using OpenLDAP 2.4.31 under Ubuntu 14.04, doing four way multi master replication. When I initially configured it, I set the data (as opposed to config) replication to be "type=refreshOnly", as described here, http://www.openldap.org/doc/admin24/replication.html#N-Way%20Multi-Master

That didn't work well, we lost insertions and and memory usage of some servers steadily over the two weeks I left it. Switching the replication to "type=refreshAndPersist" resolved both problems.

What is the reason the documentation suggests "type=refreshOnly" for data, but not for config? Should I expect any problems using "type=refreshAndPersist" for data?

Best regards, Dave Lambley