Welcome, Cassie!
It’s so nice to hEAR from you and be able to aid in planning your magical Walt Disney World Resort vacation. Thank you for visiting us here at the Disney Parks Moms Panel.
Over the years, my family has used the
Rider Switch Service a ton. With three little ones and a large age gap, it was a wonderful feature to ensure that everyone was able to ride (or not ride) the attractions of their choice. To use it, your entire party will need to see the Cast Member at the entrance of the participating attraction to request a Rider Switch pass. While the first member(s) of the party ride the attraction, the others will wait outside of the attraction. Then once the first Guests are finished, the members will switch and the other Guest will use their Rider Switch Pass to ride while the others again wait outside of the attraction.
If I understand your question correctly, your son who is not able to ride will not need to make a
FastPass+ selection as he and the other Guest will need to wait outside of the attraction while the first members of your party ride.
I hope this information helps in your planning, Cassie, but please let us know if there is anything else we are able to assist you with.
Pixie Dust,
Lauren