Don't want to claim any authority...but-- I've noticed these two things about the butterfly keyboard on my 2017 MBP. First, I don't transpose nearly as many letters as I used to, and I type a lot, have done so for many many years, so this is a very big plus. Second, I do notice some fatigue, perhaps like a very slight case of pad banging. Sort of like running on a hard surface too hard, but on my fingertips. Possibly because there's less travel and I haven't been able to back off how hard I hammer away.
Jammed keys. Oh, yeah. This is really insidious, but I've got an air compressor and for once Apple Support Network had an excellent How To-- so it wasn't too hard to sort out. (I don't know what this would be like while traveling. It really does shut down typing.)
I hope that who's ever on this switch is thinking and not reacting.
One suggestion I would like to contribute, I continue to make many of the same mistakes I've made for many years. Punctuation keys like ; and ' I often hit wrong. And many times if I just have to type in a few or only one word, like for a search, often my fingers are shifted over and it's all gibberish. There should be some tips on how to avoid, or train out of these errors. (I have put drips of hot glue on certain keys and that's helped. I hardly notice the two tiny pips on the f and j keys.) And perhaps there should be some changes in the layout to help with this, maybe a gap between some of the keys.
And what's the 'caps lock' key still doing on the American English keyboard? I understand that some people need Caps Lock, just as a year ago I needed to know the key combination for £ and €. Do something else with that area. (What would writers like? Add that and then add some practice for it. I use two commas in a row for ," which was about the only 'killer app' for me using my long long in the tooth word processor.)
And my required beef about the track pad sensitivity (my cursor jumped to another place in my text while writing this-- which is a huge improvement since they replaced the the keyboard and track pad) and I can't be the only person who hits random functions in the 'feature' strip while typing numbers.