Check out the main Genie+ thread, post1. Has all the critical info. The relevant hopping rules are:
If you plan to hop, you may apply for a LL reservation at the other park(s), but you are limited to return windows after 2pm (all regular hopping rules still apply).
i.e. if your reservation is at AK, and you try to book something at 7AM in HS, the return window will automatically be advanced to 2pm (or later). This can help with planning to some extent. The one twist that throws off a lot of folks is when you can book the 2nd LL. Unless you tap into it first, you can book it at
Two hours after official opening (i.e., not the early entry opening) of the park where your first LL selection is located (your first LL selection can be either where you are starting your day or where you are hopping to after 2pm).
Suppose your reservation is at AK and you want to hop to HS later.
7AM: book MFSR for 2pm return time
you can book your next LL at 1030 (HS park open 830 + 2)
7AM: book NRJ for 10am return time
you can book your next LL at 930 (AK park open 730 + 2)
After the booking the 2nd LL regular booking rules apply. Hopping takeaway: All else being equal it’s better to book your 1st LL at the park that opens earlier.