Actually i had seen a big improvement on my previous phone battery once samsung had released the oreo update, i don't know what feature is inside it but it definitely gave me a few extra hours.
not sure if it would work the same on this phone tho.
Unfortunately I dont think Oreo will come to this device, we keep getting promised but never happen. Always wait wait wait .. it was released last year and now we are on Android Pie
Yeah, I think this will be my last blackview phone. I mean, I'm happy from the manufacturing point of view, but not even security updates are released, and the community is M.I.A...