dc32f0cfe84def651e0e
obviously your favourite device is not supported, so direct your frustration at that device manufacturer to up their game!
I expect they build phones for the millions of people who don't give a rats ass about security or privacy, so getting them to up their game for roughly 250,000 GrapheneOS users is a non event.. but you could try!
As regards your battery, it has been identified as unreliable, unsafe, has it not, heed the warning, replace it, or trade it in for money off a new device as per the offers... the 80% limit is now redundant in your case.