But, I have expressed my concerns elsewhere here on DIS that since we'll likely have them both sit in the wheelchair, the way we used the double stroller, that people will be shooting us nasty looks, particularly if my son isn't wearing his AFOs. I know I shouldn't worry about what others think, and its bonkers that I would have to "prove" he really needs the wheelchair, but people are funny and I don't want my son to feel that kind of negativity from others.
I'm really struggling trying to figure out whether he should wear the AFOs or not. So much to consider.
There are people who will judge no matter what.
My DD can't even stand up, but we have had the situation of hearing someone say "There's a child who just has a wheelchair to get ahead in line." It was said loudly, for our 'benefit'. The apparent reason they said it was that DD was sitting on a bench with her wheelchair sitting next to her.
A lot of people assume that if someone is physically able to get out of their wheelchair, it means they don't need it. In our case, DD needs to lift her out of he wheelchair, but once she is out, she sits fairly well on a bench or chair. (Depending on her tone that day).
You know what your children need, and your family's opinion is the only one that matters.
My DD doesn't have AFOs anymore, but I do recall how hot they got when she did wear them. If you want to bring them along, but not have him wear them all the time, it would be possible to leave them either in First Aid or in a locker. All the parks have a First Aid station and rental lockers near the front of the park. That way, if you find they would be helpful, they would be there.
Another thing to think about is how stable he would be for stepping into ride cars without the AFO. For example, so rides like Pirates require 2 large steps down to get into the ride car and another 2 steps out to get back out. Here's a picture of POC boat so you can see.
allearsnet.com has a gallery of ride seating photos that might help you. They don't all show the step because they were taken originally to show the size of the seat for Pooh sized guests. I also have a lot of ride photos, but only a small portion are on the internet so far.