XDCR cluster count

We are setting up a georedundant database system that currently has two clusters nodes with XDCR configured. Next we would like to add two more cluster nodes to this setup but this is where it all gets a bit tricky.

Although I have read the Couchbase documentation several times I still haven’t found the answer to my question - What is the maximum count of cluster nodes one can have in XDCR setup? Please do note that I’m talking about multi master database system.

In the documentation and in the web I only see three cluster node XDCR setups. Can I have more clusters than that and what is the absolute maximum limit?

I would also be interested to know (if Couchbase supports more that 3 cluster nodes in the XDCR) how the Couchbase handles the data consistency in multi master setups. A link to some onlide document would be appreciated…