Does anyone know what kind of snapshotting the ME5 uses for replication? Clone, split-mirror?

We were recently considering the idea of replicating our ME5 to a ME4 that we have. After reading the docs, it looks like we would need to allow for 4 times the anticipated pool size (Source data, snapshot 1, snapshot 2, queued replication). We don't have enough capacity for that. Anyway, this led me down a rabbit hole in regard to how storage snapshots work. A description of how "clone" or "split-mirror" snapshots kind of makes me believe this is how the ME5 handles replication. 

"Clone snapshots, also known as split-mirrors or full copy snapshots, reference all the data on a set of mirrored drives. This method involves duplicating the entire dataset, not only new or updated data, which can be used independently from the original."

Can anyone confirm?