I followed a blogger a few years ago who was a DL regular. They visited WDW, and on the day they left, they went to MK and rode HM, and maybe a couple of other rides that were also in DL. They flew home, and because of the time difference, rode the HM in DL on the same day! I don't think they managed to fit in the other rides in, but it sounded like a very cool challenge to me. If I was going to do both parks in a single trip, I would definitely try to pull off a stunt like that just for the bragging rights.