[Borgbackup] Offload CPU/RAM cost to target?

[MRob]

I know for like encryption you have to do it on the source side. In case 
where backup is local non-encryption are there technique that can 
offload more CPU/RAM requirements (compression?) to the target backup 
server?

I think one idea to rsync everything to the backup server and make a 
borg backup of that on same machine but it will require a full extra 
duplicate of the backup material.