I have multiple hosts in a farm. Some hosts can access certain network shares, some cannot.
As a result it would be nice to have farming ability per processor node in addition to per workflow.
That way I can set the delivery processor node to use the hosts that have network share access.
At the moment I set this on a workflow by workflow basis, where as the most efficient would be to do the transcode across all hosts to the cache then the final copy/move on the hosts that have the required network access.
I can imagine this would make prioritisation more difficult

I'd personally implment it with a tickbox in each processor node, 'Use Workflow Farming Settings' (by default) or tickbox list to select hosts that should perform the task overriding the workflow farming.