I know it’s almost your trip- I checked touring plans and they are predicting low crowds at Uni at least in Sunday. I’d expect during week even better.
So- keep the deluxe, know you won’t have to wait in any line, and son can reride as much as s he wants with no wait. Less standing and planning and backtracking for you (fibromyalgia - horrible disease - hope you are feeling well!)
Or- go less expensive, knowing it may require not doing a ride if line is unexpectedly longer, or backtracking. Also something to consider is the express queue is usually shorter walk length wise (a time least in busier times, in slow time I don’t know how many switchbacks would be open). But money saved, especially when May not be really needed...and the ep queue often has elements that add to story that express doesn’t...sorry don’t think that was much help