Hi,
One feature that I’d love to see and might be fun to implement is that I’ve noticed some network protocols (SMB/NFS) are soon-to-be/already supporting server side copy/move operations. This is mostly useful if, like me, the Sonarr instance you run is separate from your NAS/file store and you want to save time/resources/avoid fragmentation by having the operation done server-side rather than over the network.
TBH, I’m not sure whether it is/will be transparently implemented in both protocols - it looks as though for both you may need to explicitly use it.
SMB (Supported from Windows 7+): https://wiki.samba.org/index.php/Server-Side_Copy (SMB with - requires special ioctl to be used.)
NFS (only being developed for the upcoming v4.2) - http://wiki.linux-nfs.org/wiki/index.php/Server_Side_Copy