It isn't optimized for
flow from a center inlet, sorry, I should have specified. The pattern is not circular in any ways. Nicozeg made "stepped rings" in the first design he presented. Radius is just too obvious
Getting rid of the walls will be less restrictive, and that's an open door for more performance, even if it's just a little bit.
At this point, you might consider your mounting options, because you could have an issue with the structural integrity, as I did with the 1.0mm baseplate. If you incorporate 4 posts where you had walls, and use a copper top (or thick polycarbonate, like me), you'll have that issue licked.