No surprise. I'm going to give you an answer that isn't up there. As hard as you tried to cover all possibilites, there is one that doesn't show up:
Some got worse, then better, then worse again. I think the reason that possibility didn't occur to the OP is the age difference between myself and Tuttle. I'm 51 years old. At her age (22), I would have said almost all were getting better but not by much. Several years later, in my early thirties, I would have said they were all better than they used to be.
That's because I learned to adjust over time, but it took a lot of energy to do so. After several more years of learning to "deal," dealing for so long started getting more and more tiring. For a lot of sensory issues, by my mid forties I was just sick and tired of "dealing," and just couldn't do it anymore like I used to.
One particular issue I never had when I was young was dealing with the calamity and noise of kids. I was an only child and only had to deal with that when visiting other families. It wasn't a big deal because it was never for very long and I always knew I would be going home eventually where I didn't have to deal with it at all. Between 36 and 39 though, my wife and I had three kids, all ADHD and Autistic. Suddenly home for me became a place of constant noise and calamity from which there was NO escape! It's 15 1/2 years later now and I still haven't completely adjusted to it. I'm better than I used to be, but it has added to all the rest of the sensory issues I had learned to deal with, but never with this added insanity.
It's been a bit of a long term up and down slow roller coaster for me. To tell you the truth, I love my kids to death, but I honestly can't wait for the quiet to return. I have a sneaking suspicion that when it does, I may once again be able to deal better with the other issues that have become harder to deal with again.
In the end it may result in a down-up-down-up pattern.
I wonder sometimes how well I'll deal with visits from them if they ever make us grandparents.
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I'm not likely to be around much longer. As before when I first signed up here years ago, I'm finding that after a long hiatus, and after only a few days back on here, I'm spending way too much time here again already. So I'm requesting my account be locked, banned or whatever. It's just time. Until then, well, I dunno...