Apps make 1000 decisions for you before leaving you with the remaining 10 for you to decide. UX design is a balance of deciding which decisions the user should be bothered with, while the app takes care of deciding the remaining 99% itself (mostly without you ever being aware).
When Arc was designed to remove that choice (when battery is below 10% or thermal state is “critical”) iPhones had much less battery power, so that 10% could disappear in a handful of minutes if the full UI was visible and then used intensively. That situation is a bit different now, so 5% would make more sense.
I’m not totally against changing it so that it’s always optional. Although it is one of the many cases where most of the time “the app knows best”, I’ll concede that there are cases where the user does have legit reasons to override it.
Anyway, all of this will get redone in Arc Editor when I rebuild Low Power UI there. I’m definitely going to keep all of this in mind when I come to that work! And yeah, most likely you’ll get your way and I’ll concede 