Wouldn’t this this be taken into account by a competent OS/whoever is in charge of telling the computer about the status of the battery? That is, if 30-85% were the optimal range, I would simply force the computer to operate in those ranges; go dead at 30% for example (and calibrate the battery life display accordingly).

Certainly the lower limit is limited, maybe not the upper limit. At least, my dumb e-cigs know not to discharge 18650s (which I believe were pretty common a few years ago in laptop battery packs) below 3.0V, although my charger is not smart enough to keep it below 4V or anything.

I guess you would need to lower on “x hour” battery claims if you did this, which is probably not desirable. And stuff isn’t really built to last.

So I guess I’ve talked myself out of believing this could ever be a native manufacturer/OS thing.