I wouldn't want to see Witness voting and Proposal voting lumped together like this.

Witness voting is all about code versions. Issues here can lead to successful attacks against Hive.

Proposal voting is granting funds to projects and so forth. It can be an inconvenient drain if abused, but it won't break the chain.

Lumping them together is akin to placing the engine on the same service schedule as the food tray.