You can also set the device to have close to zero Allocated Time. This would be done via a simple "hack" in the Web Dashboard; The Steps after you login into the Web Dashboard, from a desktop browser, and click on the child device and then Screen Time Tab:
Move the mouse to the Allocated Time Dropdown and Right Click to Inspect.
Here, you will find code such as:
<option value="1800">30 minutes</option>
Change the value of 1800 to what you want – Example 60 would mean 1 minute.
Then when you select 30 minutes, you would really be getting 900 seconds which is 1 minute.
Want less, set it to 5 seconds.
Tip: The Encouraged & Always Allowed Apps still work outside of Allocated Time. If you want a completely tech free day, then you should ensure that there is no Scheduled Screen Time set for that day and that you have no Always Allowed Apps.