Sorry, there is no relevant document about VBO at present. But I can tell you about the VBO dts configuration here:
bootloader/uboot/board/khadas/configs/kvim4.h
common/arch/arm64/boot/dts/amlogic/mesont7_an400-panel.dtsi
The board VBO electrical connection is selected as follows: lcd1->vbyone_1
The yellow box indicates that you can configure VBO related parameters.
The default resolution of the code is 3840*2160.
