I've seen VSL address it but not deeply, that adding an instance in and of itself is somewhat negligibly more resources use; ie., dozens of instances, a hundred of 'em may become meaningful.
For me it's organization and the visual, too much more than I can display without scrolling and I'm thinking new instance. Then I kind of create families for instance but not severely.
I have a hypothesis that the threads per instance feature might work best with the one instance approach.