i found in Community Edition a new feature to replicate data. I read also that an WAN accelerator part exists but is not included in free as expected

So i am wondering if this replication feature makes any sense over WAN with free edition. Forever incremental will be no problem, but what happens on full backups?
In case of transfering existing active full or full synth. backup, does it compare what already exists on target location or does it transfer everything again over network. As WAN accelerator is described to speed up to 50x, i am afraid it will be the latter one.
Or is it possible to use a 2nd B&R server in remote location which helps to limit transferred data in case of synth full?