This is MIUI battery optimization service that aggressively kills apps in background for a negligible battery gain.
This device already has more than efficient chip, and does not need this aggressive background app killing to get to 8-10h of SOT. It also has the fast charging.
So my advice would be to remove com.miui.powerkeeper trough ADB, since I did that my device works fluid like a flagship. No aggressive background app killing at all, so the potential of this device can be used fully.
Since I don't play games, SD680 has more than enough performance for a normal daily usage.