I think the system only really works if all rides (or at least all E/D tickets) are in the virtual queue system. In my scenario above, The guest wasn't using any extra ride capacity, however they were clogging up some of the not ride experiences.
The system works at Volcano Bay, but they also have massive "people eaters" that are always ride anytime. 2 lazy rivers, a massive wave pool, a "lagoon"/pool, beach, trails, and of course just relaxing on a beach chair.
Magic Kingdom has some, but would need more of Tiki Room, Country Bears, Tom Sawyer, Casey Jr., Philharmagic, dumbo playground, ect
EPCOT is probably best suited to move to this over any park, because world showcase can soak up tons of people waiting for their return time.
DHS has the least to do: Data Pad, One Man's Dream, and Launch Bay (I assume shows would be limited with your standby quene)
AK would have the animal/Discovery trails and Rafiki's