This app was created for OnePlus 7 Pro, when a11 was released for this phone a disturbing scaling issue was introduced. The only way to fix it is by locking the refresh rate to 90hz

Practically it has 2 buttons that execute 2 different adb shell commands:
adb shell settings put global oneplus_screen_refresh_rate 0 or 1

Additionally it can support and help other One Plus users lock their screen refresh rate to MAX using 'Lock to MAX' option.

Open source project, you can find the code in the following repo:
https://github.com/llabropoulos/refreshRateChanger