[Solved][ Hiding Android 10 Navigation Gestures Bottom Bar ]
Note: I have reverted back since the change causes lots of other unnecessary hiding during landscape and other modes.
ADB required. Connect.
adb shell wm overscan 0,0,0,-110
Now you can set Display Size as whatever you want or width size, no need for below 410 smallest width.
Gboard's Bottom Bar also hidden away.
To reset : adb shell wm overscan 0,0,0,0