The proof needs to be in the form of doctors notes or something similar.
Access to Healthcare is needed to produce doctors notes.
Access to health-care is not a given, especially in this country right now where insurance is largely tied to your place of employment
Even if you have access to Healthcare, mental Healthcare access is a whole other issue
Plus, medical practitioners historically overlook "invisible" chronic issues such as fibromyalgia in younger people. Especially women.
So, requiring proof for a DAS pass sounds good on paper. But in practice makes it much more difficult if not impossible for people who need it.
That being said, I'm just parotting what I've heard from friends who either use DAS or work guest relations about issues they've seen with Universal's system and fears of Disney adopting it. So I'm far from an expert
Of course, this thread has gotten WAY off topic and I definitely take some blame there lol