As for AFR, the client takes care of the work.
servers are essentially just network
accessible file systems, that aren't aware of each other, and thus,
don't replicate between each others at all.
So for n mirrored servers, the client bandwidth increases n-fold?
That's quite shocking...
Yes, it is quite shocking - and doesn't make much sense to me, either.
Instead, you can have the servers be responsible for AFR, and let the
clients be unaware of each other. This solves the n-fold bandwidth
issue entirely (and seems more "normal").