I'm not on Beta or on the official finished Android 11 Samsung One Ui 3.0.
I'm on Android 10 and Samsung One Ui 2.5 but the first thing I did do was change my button on my phone to allow it to shut my phone down.
I truly hope this can be achieved in Android 11 and Samsung One Ui 3.0 @littlephone
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 3.1/ Android 11.