Well I did flag up the 6 out of 11 in my immediate teams who have some form of ergo equipment (chairs, footrests, mice, keyboards) for neck/back or upper limb issues. One has a known dodgy back; one has arthritis in her neck, another has severe arthritis in her hands but can still mouse... I asked boss3 to check with occy health how many in our division had "alternative access" devices and he went a funny shade of green as he made notes. This is why the consultants were sposed to be bought in...
The issue is as much expecting me to educate them on how to meet my access needs (not my job) as it is shite project management. Neither project manager is techie and as you say the IT bods can flummox them with bullshit. They think the law is on their side; I know it isn't, but I know ONLY a disabled person directly affected (me for example) would be able to enforce it and that's hugely risky as well as exhausting.
I will sue them if I have to. But I have to "play the game" up to that point. Increasingly tempted to draft a freedom of information request on what specialist IT consultancy they have had on this and other projects in the uni... That'll freak them the fuck out.
As for the deaf literacy/hearing stuff, it's not widely known so don't beat yourself up over it. It's not even well researched in non signers. Being willing to listen and recognise "there's stuff you don't know" is the important thing. I'm still working things out for myself cos "I seem to function well" much of the time but only by working hard to do so and I have massive gaps in weird places...