I charge whenever I need, quite often under 20% and my battery starts acting up after about 3 years, when I'm anyway looking for the next flagship. Last 2 phones were Xiaomi
I'm on my 2nd Xiaomi flagship and I think had to request unlock and wait for a day or so. Or use some trick to skip this step. So in theory after (if) I get my next Xiaomi 15 or whatever it will be, one unlock per year should be fine.
The idiotic thing with Firefox mobile start shortcuts is that it always opens in new tab. So you open new tab (shows start screen), click any shortcut icon and it opens another tab. Why? No idea.
Get old HP thinclient T510, or Igel M340C. Got a few of those practically free online. Has Via Eden 1.2Ghz 2 core. Not powerful at all. But cold. Mine runs on hot summer days approximately between 40-50C. HP has I think 19V power source, Igel runs on 12V brick.
I charge whenever I need, quite often under 20% and my battery starts acting up after about 3 years, when I'm anyway looking for the next flagship. Last 2 phones were Xiaomi