I’m the one who posted that I was disabled; I posted it in a very light-hearted way (I said “so nyer!”), and also said that the devices aren’t all about saving labour anyway.
That would probably indicate that I wouldn’t be offended by you asking for specifics, and I’m not offended. I am a little surprised, though. Almost all
“labour-saving” devices also help people who have physical or mobility problems - I mean, labour is physical labour, and some people have problems with some aspects of physical labour. Seems to me it’s obvious that labour-saving devices can be useful for people who have disabilities.
FWIW, the light switch is because I have difficulty lifting my arms due to problems with my shoulders. For most of the switches I just get on with it, but one of them is particularly awkward to reach. Going to another room to speak to someone, or especially going down the stairs to do that, is obviously more difficult if you have difficulties walking, like I often do - rheumatoid arthritis (plus a couple of other things), so it varies a hell of a lot.
And just not having to use my hands is sometimes, er, handy. Obviously I’m using my hands to type now, and I do that all day, but they get tired, so having a hands-free option gives my hands a break. And if I have to use my hands to help get around because of my legs not working properly that day, then my hands aren’t usable for things like light switches at all.
An acquaintance of mine installed Alexa for his mother to enable her to continue living independently for a while. It was all little things, but it helped. They’re often used as assistive devices for people with a wide range of disabilties.
Anyway, for the general question, in a social situation I wouldn’t be offended if someone asked what my disability was, but also would generally not want to answer, at least in detail. For them, they’re just curious (especially because I’m young and look healthy), whereas for me, it’s an unpleasant topic and also extremely boring compared to everything else, and I’d rather talk about other stuff when I’m out being sociable. So I’d tell them briefly, then change the subject. And if they started saying shit like “oh yeah, my friend had that in her little finger and drank aloe vera and it all went away” then I’d probably change the person I’m talking to, not just the subject.
Online it’s fine as long as me giving a very brief answer or none at all is met with acceptance rather than a demand for more details. Also I can answer in my own time, like I have now.
It would also get annoying, not offensive, but annoying, if someone asked for further details, especially if they contained really obvious “advice.”
At work I would expect it only to come up in specific circumstances if it’s from a superior. Sometimes it’s relevant.
From colleagues, well, it varies. There was one time I was in a staffroom and I said that I had rheumatoid arthritis (in context of something else) and there was an audible intake and exhalation of breath from everyone there - they’d obviously all been wondering but hadn’t wanted to ask.
It is a weird one because it can sometimes really mean that, unlike in the movies, you limp on one leg one day and the other leg the next day. 
Sorry for using “I” rather than generalising, but it’s difficult to generalise. Every person with a disability will feel differently so I don’t want to try to speak for everyone. I think my POV is fairly common, but it’s certainly not universal.
FWIW I’m officially disabled in the sense that I get PIP - a UK benefit that’s for people with extra needs, nothing to do with being able to go to work or not (and really hard to get)- and have a blue badge for when I’m driven somewhere. But in some contexts I wouldn’t expect “disabled” to be that strictly applied.
Also there was no “deference” expected. That’s an odd word to use - I’m not sure what you mean by it at all. It doesn’t sound like you mean anything negative, which is one of the reasons I’m baffled.