Personally I had to unlock the FPS through adb with this commands:
adb shell settings put system peak_refresh_rate 1
adb shell settings put system min_refresh_rate 1
After running those I’d not mess with the developer options with the “Force peak refresh rate”, it does break the changes made by ADB.
It does work in most of apps I think. It worked for me in Hatsune Miku: Colorful Stage, I have game mode disabled. Hence why I think it would work in a normal app.
Also take note that some apps limit the frame rate by their own. Some games limit the frame rate to 60 while there’s a loading screen or similar.