Booking for others at different parks

I’m going to WDW with extended family (and will probably ask many more questions as our trip approaches). We’re doing two park days together. One day in MK with everyone and then the next day the group is splitting with 12 going to AK and 3 going to HS. I’ll be going to AK. However, I am the planner/scheduler. I am connected to everyone in MDE. My question is, can I book lightsaber experiences and an ADR for HS if I’m going to AK (and booking an ADR there)? I don’t have a hopper. I also have a leading reservation since I have to get ADRs for so many. Maybe I need to add someone from the party of three to my leading reservation?

Should really only be an issue if you are trying to book a reservation at the same time at AK and HS - it will make you choose one or the other when booking if they are around the same time. In that scenario it is helpful to have someone else that you can set as managing the reservation when booking. Probably worth adding one of the three to your leading reservation to be safe since its not something you want to have to do when your ADR day opens.
There is no restriction about having a park pass for the specific park to be able to book an ADR/lightsaber experience.

I would think since ADRs require a park pass reservation, I would think as long as you are booking the correct people at the correct parks for their ADRs you should be fine.
But this is a very specific question that I highly recommend you call Disney or use their online Chat to ask a Cast Member just to be on the safe side!

No, making an ADR does not require a park reservation, but getting TO that dining site will require the proper admission (ticket plus APR or hopper). When you make the ADR, you only need to give one person’s name, number of people, and a credit card (for charging any no-show penalty). Whoever actually shows up for that ADR only needs to give that one’s name.