My kids are older now so we missed out on the screen time option but I tried many other tricks over the years. When they started it was wifi only iPods that I could stop the internet connection on at a certain time each night.
I could go on with examples but might as well get to the point. They will find a way around pretty much any block you put up. Best to talk to them about things and trust they can handle it with verification on a timeline you're comfortable with. You cannot shelter them from everything. Turn the feature on, don't avoid the talks, and hope for the best. They will be where you are one day too and be just fine in the end.