Of course Clover is a superior tablet in every respect, but battery usage at standby doesn't seem "normal" by any measure. I don't know if it is Xiaomi's fault or this ROM's, or my settings. I'm getting 20% battery use over 7h of standby, on airplane mode.
Hi.
It has to be xiaomi, s kiss of death. I observed terrible result in miui 9. It was a bit better in miui 10.
Battery in standby will work like you want if you have rooted device. I configure all my devices, and no voice devices are able stand-by during month and half. The all time working gsm modem shorting this.
What to do? In own script or rom configuration (if rom has it) turn off wifi and mobile data on smartfons and wifi and gsm modem on tablets. Additional turn off nfc, bluetooth... on every lcd lock. Turn it on, on lcd unlock.
Use L Speed with battery configuration.
Use Greenify for restricted hibernation all not needed apps.
Use Wakelock monitor for detect problematic apps and hibernate it in Greenify.
Use Netguard or other firewall for cut intertnet for not needed apps.
Always check if not needed apps do not auto start with system.
This is all. You need only root and xposed. I suggest to use too the XPrivacyLua if yor privacy has any value.
If you say, this is not possible in your rom, it can be true. I configured it on non-gsi AICP mordiford.