From an API perspective, large scale block edit methods could be included.
@DDoS is looking into making the Voxel system more general.
For example, you could take a snapshot of an area, edit the snapshot, and then submit the entire snapshot in one go. Internally, the engine could do the update more efficiently. Any per method overhead would only happen once.
If the engine sends a block change event for every block changed, it is very slow.
However, if you update a volume, it can send 1 event with the VoxelVolume of the changed area. This means that a protection plugin can just check if the entire cuboid intersects one of the protected regions. Even if it does, it can iterate over a sub-section of the volume faster than receiving and ignoring a large number of block change events.