I stopped trusting screen time and have an automation that turns on Color filters automatically when a focus filter is turned on or some app like YouTube is run… Also, when that focus mode turns off it triggers the turns off Color filter using Apple shortcuts.
Greyscale allows us to use the device but is very off putting so people including myself realize it’s time to put down the phone.
Apps like freedom and onesec never worked for me.
Feel free to try it, share your experience if it changed your habits. Or if you have a better solution, please share.