The number entry component needs to be targeted at a column - there is no getting away from that. I guess my question would be what are you doing with the entered value? ie. what is the action on your “Upgrade” button doing? You didn’t explain that in your video, and that’s probably the most important point - as presumably that is where you will want to use the entered value?
It seems to me that the functionality you are looking for here is that which you get with a Custom Form, and you’re kind of halfway there…
The reason you don’t see an option to set a default with the Number entry is because you’re using it outside the context of a form.