Do I correctly understand Park Hopper Plus?

I promise that I can read, but I’m not positive that I’m understanding if the Park Hopper Plus will work for what I’m trying to accomplish.

I am staying at WDW before a cruise out of Port Canaveral that departs on July 5. I mostly didn’t want to be trying to fly into the port area on July 4, and was able to accommodate some extra time off. Fly into MCO July 2, drive rental car or get a car service/shuttle to the port July 5. So July 3 and 4 are entertainment days.

I have done resort-only stays and could do that here. I’ve also discussed hitting a water park one day. However, DS10 would love to see the new Galaxy’s Edge stuff at HS. We’d also maybe like to see the July 3 fireworks inside MK. We could water park on July 4.

From what I read of the Hopper Plus, we could use it for admission to HS on July 3 morning and hopping to MK that night for fireworks. Then I think we can use the plus admission for the water park on July 4. When I go through testing a ticket purchase on Disney’s site, it says “your tickets are valid for admission to multiple theme parks on any one day from 7/3/2020 to 7/4/2020. Your ticket also provides one visit to a water park … during the same date range.” So I think that means what I plan works, yes?

Also from this fine print, if I buy this type of ticket in advance but when making FPs or whatever (flights on 7/2 still unbooked) decide to do my park day on July 4, it looks like I can do that even with the pricing being for a specific day (I haven’t been since this new pricing took effect), but would have to do the water park 7/3, correct?

Yep - You can visit the parks on one day and the water park the next day in your scenario, plus choose either the 3rd or 4th for either option.

You can also visit multiple theme parks and use the water park the same day - but that’s a lot of stuff to squeeze in!