Great to hear!
So was there ever a case where you showed up on time for one bus and felt like you'd be delayed to the next because the first was full? With EMH touring patterns there would be times of day when there are heavy use, like from 11-12 leaving an EMH park.
And how was it getting on rides? You could do lots at the AK being rope drop and then you had FP+ lined up for MK, but then HS and Epcot... If we were to try a 4-park day, we would have to ride at least a major and minor attraction at each park. That would mean getting on Test Track and Rockin Roller Coaster in the afternoon without a Fastpass...
So if we were to do a 4-park day, I think I'd set it up with AK first (being the furthest from our base) then take express to HS where I'd prearrange FP+ for TSMM, ST, ToT... then walk thru the Boardwalk region to Epcot where we could do Figment, TT and have dinner, then express over to the MK. From there it's easy to get home.