Switch between displays, scales and Steam Big Picture (depends on https://github.com/imniko/SetDPI)

Exit Big Picture.bat

@echo off

start steam://close/bigpicture

:: Set display scale to 150% on TV
SetDPI.exe 150 1

:: Switch to internal display only
DisplaySwitch.exe /internal

Go to Big Picture.bat

@echo off

:: Switch to external display only (TV)
DisplaySwitch.exe /external

:: Set default audio device to TV
SoundVolumeView.exe /SetDefault "NVIDIA High Definition Audio\Device\LG TV SSCR2\Render" all

:: Set display scale to 100% on TV
SetDPI.exe 100 1

:: Launch Big Picture Mode (Steam)
start steam://open/bigpicture

Go to TV.bat

@echo off

:: Switch to external display only (TV)
DisplaySwitch.exe /external

:: Set default audio device to TV
SoundVolumeView.exe /SetDefault "NVIDIA High Definition Audio\Device\LG TV SSCR2\Render" all

:: Set display scale to 100% on TV
SetDPI.exe 150 1

Toggle Big Picture.bat

@echo off
setlocal enabledelayedexpansion

:: Check current display mode by attempting to read from a status file
set "statusfile=%temp%\displaymode.txt"

:: If status file doesn't exist, create it with 'internal'
if not exist "%statusfile%" (
    echo internal > "%statusfile%"
) else (
    :: Check if file is empty
    for %%? in ("%statusfile%") do if %%~z? equ 0 (
        echo internal > "%statusfile%"
    )
)

echo Debug: Checking current state...
echo ----------------------------------------

:: Read the status file properly (this handles empty files better)
set "currentmode="
for /f "usebackq delims=" %%a in ("%statusfile%") do set "currentmode=%%a"

:: If still empty, default to internal
if not defined currentmode (
    set "currentmode=internal"
    echo internal > "%statusfile%"
)

echo Status file: %statusfile%
echo Status file content: [%currentmode%]
echo.

:: Clean up any hidden characters
set "currentmode=%currentmode: =%"
set "currentmode=%currentmode:~0,8%"

echo Cleaned mode: [%currentmode%]
echo.

if "%currentmode%"=="internal" (
    echo Switching to TV / Big Picture mode...
    echo.

    :: Switch to external display only (TV)
    DisplaySwitch.exe /external

    :: Set default audio device to TV
    SoundVolumeView.exe /SetDefault "NVIDIA High Definition Audio\Device\LG TV SSCR2\Render" all

    :: Set display scale to 100% on TV
    SetDPI.exe 100 1

    :: Launch Big Picture Mode (Steam)
    start steam://open/bigpicture

    :: Save new mode
    echo external > "%statusfile%"
    echo Mode saved as: external

) else if "%currentmode%"=="external" (
    echo Switching to internal display...
    echo.

    :: Close Big Picture Mode (Steam)
    start steam://close/bigpicture

    :: Set display scale to 150% on internal monitor
    SetDPI.exe 150 1

    :: Switch to internal display only
    DisplaySwitch.exe /internal

    :: Save new mode
    echo internal > "%statusfile%"
    echo Mode saved as: internal

) else (
    echo Unknown mode [%currentmode%], resetting to internal...
    echo internal > "%statusfile%"
    echo Please run the script again.
)

echo.
echo Done!
timeout /t 30 /nobreak >nul