The main features that distinguish BaikalOS from other ROMs:

1. Power saving modes.

In BaikalOS, there are a lot of changes in the processing of background activities. This applies to the entire system. This includes wake-up alarms, background task scheduler, and background services permissions. ROM behavior is quite different from Google implementation.

 - Aggressive blocking modes for background apps. 

 - 'Stamina' mode in which all applications that are not excluded are completely blocked.

 - You can completely block Google Play Services. But at the same time allow them to work for applications that need it (in the application profile)

2. Application Profiles

 You can set parameters for each application. These settings will be automatically applied on app launch.

 - App pinner. The app will not be killed my OOM and LMK. Only in case of critical memory shortage.

 - Performance profile (balanced, limited, performance, gaming, battery)

- Temperature profile

 - Screen brightness

 - Screen refresh rate

 - Background work. You can allow or block the app from running in the background. Prevent the app from autostart on boot.

 - Allow the app to use Google Play Services if they are blocked in the general settings

 - Set the app audio volume scale. 

 - Manage Audio Focus. The app can ignore requests from other apps and continue to play audio in the background. Or do not send requests the other apps to mute.

3. Performance Profiles

 The system has a set of performance profiles that can be assigned to applications. Some profile settings can be changed. 

 - Minimum and maximum CPU and GPU frequencies

 - Core control (disable/isolate cores by load)

 - Sched boost and GPU boost

4. Sound

 - You can disable sound effects 

 - Manage Bluetooth codec priorities

 - SBC HD - for each device, you can enable SBC Dual Channel and set the maximum bitrate. The sound quality of SBC HD is higher than AAC, and at bitrates above 450 Kb/s is higher than APTX

 - Duplicate the sound to the speaker when the BT/Wired device is connected. Separate switches for notifications, assistant, or the entire sound. Especially relevant for automotive use.

Well, all sorts of little things like Edge Lighting. 

And you can return media player from Quick Settings window to Notifications as it was on A10.

The rest is from AICP. BaikalOS is made on top of AICP and everything else is similar to it.