Interesting concept.
Personally I think it is a bit silly to say one has to do repeats, and no circles or varied routes.. If one was to actually climb Mt Everest, it would be one mountain, but not doing the same section of trail repeatedly.
8,848 meters (29,029 feet) in a day would be impressive no matter how one arrives at the number.
I find anything over 1 mile of climbing in a day is a hard day. Two miles? But doing 5 1/2 vertical miles of climbing would be just over the top.
There are some killer half century rides in Portland with about 7000 to 8000 feet climbing in 50 miles. Doing one wipes me out. Doing all 3 in single day would be insane.