They originally tried to deny me back when they first switched to the
DAS, so I tried without one, had an issue in the queue, the next time I came to the park, I explained what happened, never had an issue since (ok, once I had a CM question how I handled the rides themselves and that was a fair question, but as I pointed out, 5 minutes on a ride and 10 minutes or so Ina FP return queue that I can usually work my way back through if all else fails is a far cry different than an hour in a queue which I can't readily get of) and immodium doesn't work for me, so not an option there.
And the fact that I can't easily get out of the queue to reach a restroom can lead to panicked attacks, of course my wife ends up with panicked attacks in crowded queues anyway, but since we are always together, I just get the DAS. Sometimes, I do have to explain this part too, but not usually.
And yes, some queues I can get out of, but many are near impossible, especially on days that I need an
ECV. This is one of the reasons I haven't done Indiana Jones at
Disneyland very much, even with a DAS, because the queue is so physically long to get into and out of that it can be an issue, but I just recently found out that there is a bathroom by the elevators, you just have to ask the CM there to use it, so I might do so in the future.
And yes, you should tell them that it hits almost instantly and you have no warning or ability to go before it hits. If you have tried without a DAS and had issues, be sure to clearly tell them what said issues were.