i don't know anything about those units, but here's my advice and from what i've heard. the units that are open late are open for elk "control" for lack of a better word. the areas are managed for something else in other words and wdfw doesn't want the elk there. my buddy was interested in the late archery deer hunt in the swakane and there are areas open over there for any elk or any bull or something like that. he called the biologist for the region to inquire about the deer. the guy talked his ear off and gave him all kinds of info. call the biologist for that region. what he did was call the wdfw region office and they gave him the number for the biologist for that region. it's worth a shot and the bio he talked to was very helpful.
let me know what you find out.