I have a huge (~10GB) amount of data that hardly changes but is shared
among 4 PCs (plus the iFolder Server). If I set up an iFolder, I need to
exchange the complete set of data between the server and each client,
resulting in 40GB traffic.

The data is already there on all of the 4 PCs (previously shared using
rsync) and could be copied into the Simias data directory on each client.
If I try to do, there seem to be conflicts for each file that I manually
copied in there.

Am I missing something or is this not possible?