Actually, it is up to the CMs at each attraction as to how/if a particular GAC accommodation will be handled at that attraction at that time, and it might be different if you return at a different time or different day. That's regardless of the need, not just visually impaired.
That is true and should be explained o people when the GAC is issued in the first place.
While I understand what you are saying, there are certain stamps that are VERY specific. I understand that there are times that one may need to wait for accomodation, but if they aren't going to do what is on the stamp, well then there is NO point in my even bothering with that attraction and they should say so upfront. Thank Goodness, I have never encountered issues with CMs not honoring what is stamped on my GAC. I guess I will thank my Lucky Stars that I have gotten 'good' or 'well trained' CMs!!
And I get the difference in how your accomodation can be handled. I experienced that as a solo traveler on my trip this past January. But one of my stamps, when it comes to many attractions, there is only one way to honor it. So you either do, or you don't. Luckily, I have had wonderful well trained CMs and have not had any issues with it being honored!
'good' or 'well trained' do not necessarily have anything to do with it.
There are 2 words printed on the front of every GAC - "where applicable"
And 2 words printed on the back - "operational considerations"
And the stamp itself has 2 additional words - "where available".
Available can mean "does it exist", but can also mean "it exists, but is not available for use right now".
There are attractions, specifically in the past year, where GACs are not being used if the regular line is 15 minutes or less. People have posted about it, specifically for Pirates and we have seen it on Aladdin and many other attractions.
There are quite a few posts on this board where people were told that GACs were not being used at the attraction at that time when the wait in the regular line was short.
There was one particular thread where a woman posted that she was denied use of a specific way of entering Pirates and felt the CMs were "wrong" and "poorly trained" because she knew about that entrance and had used it in the past.
As it turned out, she posted enough that a CM who was working Pirates at the time sent me a PM because she did not feel comfortable posting on the thread.
The entrance the woman was talking about was "not available" because a guest had a medical emergency that entrance was being used for at the time.
The woman had been told to use the regular queue, left side if they wanted to ride because the wait was short.
I also have un-official confirmation (because WDW does not publicize anything official about GACs) that the information in post 6 of the disABILITIES FAQs thread is complete and accurate, specifically this part:
Is it treated exactly the same each time and/or at each attraction?
No. Even on the same attraction, the GAC is not always handled the same each time.
Exactly what happens depends on how busy it is, how many other people with special needs are there at the time and staffing.
Some times you may be sent thru the regular standby line, ocassionally another access; Occasionally the person with the GAC and a member of their party will be given an alternate place to wait while the rest of the party goes thru the standby line - and then meet up with them when they get to the front. Sometimes you might be given a slip and told you can come back at the time written on the slip (usually equal to the standby time); very ocassionally, you might be taken right in. It depends on what they call "attraction considerations" (which is basically the things I listed in the second sentence).
What happens will also depend on the stamps on your GAC. For example, if the GAC is for a place to out of the sun, you will be routed to the regular line if the sun is not a problem when you arrive at the attraction.
If you come back later, you may be handled differently. Even on the same attraction on the same day. People sometimes think that means one of the CMs did something 'wrong'. What it usually means is that conditions were not the same both times.