I have to mention the containers I have used now have lots of holes, not sure how exactly that influences the bottom water levels but it is not the typical 1 hole in the middle container which is what traditionally pots and pottery have always been, but 33% of the bottom is open with holes and there are 2 canals crossing each other that let air flow around.
The typical ceramic pot would be flat entirely and with 1 hole in the middle, at least in my experience.
I assume that having 2 canals like a cross cross that are higher up than the true bottom and lots of large holes must have some sort of influence of how the water sags at the bottom compared to 100% flat bottom and single hole in the middle. Now how much difference that it makes I do not know but since we got technical I wanted to mention that.
