Thank you for the replies. I'm still figuring out the Park Pass Reservation system, and I was scared to click the cancel link because I didn't want to cancel for the whole party. You are correct that the cancel link brings you to a page where you can select the "cancel" party members and the others stay in a "keep" section. This is exactly what I needed...thank you for that info!
In case it helps anyone else, I also discovered that a single park pass reservation party must be the same type of ticket holder (resort guest, AP, theme park ticket)...you can't mix types. But you can make multiple reservations for the same day and park with different party members...everyone doesn't have to be on the same PPR group! So I was able to get a reservation for the four AP people and a second reservation for the theme park ticket people. This is also the way you can "add" people to an existing PPR...just create a new PPR with those people (or multiple PPRs if they're different ticket types) and they'll be listed on your Plans in a different section.
As for the unlimited resort reservation PPRs, two people on our original PPRs during our July 11th and July 25th resort stays are FL resident 4 day theme park tickets, and when I tried to add them to a PPR for September, it said their 4 days have been allocated, which makes sense that the total number of ticket days overrides the resort-ness of their PPR use. So I had to cancel their July PPRs to make them available for September. The reason for all this shuffling and madness......
One of the six of us is a Silver AP, which is blocked out for the summer. We figured we'd be able to upgrade his pass to Gold or buy him a 4 day ticket to open up the summer, then the freeze happened and we were stuck. "Later this summer" for unfreezing 2020 ticket sales is too uncertain for the July 11th trip and probably the July 26th trip too, so we had to shuffle to get some form of PPRs for the entire group when we all can go, which is September (Silver not blocked out and 4 day tickets expire on 9/30).
Thanks again for the help. i appreciate it.