Lightning Lane Multipass and Lightning Lane Singlepass Questions

Kind of a random question but if I have a lightning multipass booked for my entire party but some people don’t want to go on the ride, is the best option to have them scan into the ride and then walk away from it so it frees them up for me to book the entire party another ride or after I scan in to get on the ride do I just cancel it for the people who didn’t want to go on it?

A little context, my wife and I, our 4 year old son and both sets of our parents are going to be going to Disney next week. We’re staying at Pop Century so I was able to book all our rides 7 days in advance and was able to get all the big ones we wanted. We have rides like Tower of Terror and Everest booked that I know my mom, my mother in law and my son won’t want to go on (my son seems to think he’ll do Everest after watching some POVs but we’ll see what his thoughts are day of… he said definitely not Tower of Terror because of “ghosts” lol). It’s not the first ride we have booked for the days because I know you need to scan into one to then open up the opportunity to book more but they are either the second or third ones we have pre booked for those days.

Also I booked single pass lightning lane for our son to do guardians. We weren’t sure if he was going to want to do it but wanted to make sure he had the opportunity to do it with everyone else who would be doing it. Mother in law didn’t want to go so we won’t need to worry about child swap or anything like that. If day of he doesn’t want to go, is there an option to refund? I’m not worried about losing out on the money but I was more so curious. If we lose out on the money no biggie!

Finally, we booked Rise and Avatar but didn’t think my son would want to do them cause some of it seems intense. If he’s doing alright and we feel like/he wants to go on it either of them, am I able to add another guest to our already bought singlepass lightning lane at the same time slot since he’s in our party? Not really sure how that one works either.

Thanks in advance for any insight here!