Seems like an oversight! You should switch battery saver turning off at 80 percent.
Locking charge to 80 percent but battery saver only turns off at 90 percent...
Needs to be fixed by someone lol.
If you do not use the 80 percent thing, does GrapheneOS use the same thing where it automatically slows down at 80 percent and doesn't hit 100 until you wake up like stock?