I'll start with the OPer first because I know I'm going to wander a bit on my message as this gets put down...
(For anyone coming in late, the kiddo has autism, can't walk or help transfer, severe epilepsy, a feeding tube, is incontinent and cognitively disabled, we are not trying to get a free ride, but just make the vacation possible.)
Oof. I will admit, it's easy to read your opening lines and think this way. It's something we see often enough and the stories of people gaming the system are matters of high drama entertainment. I'm sorry to have fallen into that thinking often enough, but I think most of us understand what you're looking for (if not what you're going through.)
So here's some practical advice... Get to the park and do your best. After a few hours go to guest relations and just lay it out for them. GR CMs really, more than anyone else in the park maybe, really want to fix your day if they can; and they have the power to do it. There is a great YouTuber named Jenny Nicholson, a former CM, who worked in GR for time and the sort of things GR does for guests on the regular is just impressive.
Tell the GR person you've got the
DAS and what problems you're hoping the DAS will mitigate, and you are doing your best but you've been in the park this long and have not been able to get kiddo through many lines. She's missing out and she's hurt by that.
As an parent and advocate for a disabled person a lot of people, especially parents, get steely eyed and stone faced when dealing on behalf of their kiddo and sometimes you really need to communicate the feelings. Put it into terms of how you feel and how the kiddo feels because those aren't quantifiable things. There's set of numbers, rule, law, or policy that can be brought back in reply to a person honestly doing their best and failing.
Then issue the ask. And make the ask reasonable. Two things tops, whatever they are. "If there were just some way to get her to see Cinderella she would smile about that for months.", "We're probably going to have to leave for the day early, is there any way we could get onto the Peter Pan ride before we go?"
You give GR an opportunity to pull your vacation out of the tank and accept whatever help they can or can't give you. There simply may not be anything they can do. Any help they could provide would require GR communicating at some length with one or more attractions and if the park is very busy, they might just be stretched too thin.
If you get some help from GR, try your best to leverage that against your kiddo to get her to maybe put forward a little extra effort in the lines of a couple other attractions and just like that you get a couple attractions instead of none. Yes, you're asking for special help. But if your day is going like you describe then you're already not in the lines much at all. It's hard to hold wanting two or three experiences a day in exchange for your cost of admission.
How do you.manage waiting for anything and everything else in your life? Certainly the wait can be longer than 15 minutes! Being in a Car for example. Did you fly: there is lots of waiting in that. How did you.manage the line at disney Security? Probably the transportation to the Parks took 15 minutes or longer....
I'm not an autism expert by any measure, but if it's anything like having a panic/anxiety disorder the problem may not be the waiting at all. I suspect the problem comes from the child's reaction to proximity to the other people in line and/or exposure to sensory and perception stressors that exist in crowded and exposed spaces.
Hopefully you can get some things accomplished but there is no DAS accommodation to impatience (autism-based or not).
Sometimes something we are about to say or type totally doesn't sound offensive while it's inside our own head. Perhaps describing the special needs of a non-ambulatory epileptic autistic child as impatience is that sort of thing for some people sometimes. I don't know. I do believe, or at least would like to believe, that I'm not the only one to find such a thing, written out like that, distasteful.
And repeated exposure in order to acclimate the person, is the only solution if you aren't going to lock them in their house forever!
...
Oh I know. But unless you *are* Bubble Boy, it is a disservice to expect that everyone cater to your special needs so that you can remain in your "bubble".
The quicker access the OP is looking for is one of the complaints against Disney by that lawsuit that got shot down, isn't it?
Quicker access ~is~ a major part of the lawsuit v. Disney. But what the OP was describing (as I'm understanding it) wasn't so much the wait but the requirement for the child to be present in line for the entirety of the wait.