I really like arms race Pool Day, as you get straight into the action. But Pool Day is maybe a bit too cramped. However the overall size and base layout is excellent but it could use some more gimmicks and hide spots than just the toilet fighting offers (which I like, excellent feature!) and the ceiling beams (which I don't like to use). This picture is just some "wild ideas!" I came up with, like the pool tunnel and a deep end for the pool connecting to the smaller pool. But I can't draw in 3D so I can't draw for example that the ceiling beams over the sink could have a small gap / opening out to the pool area from some spot so that you could also defend from there. Where I have drawn the air vent labeled Bond hatch, there are actually some narrow windows on that wall, and even a small access space behind those windows could offer new spots to counter the opposite sniper's ledge I have drawn. But the Bond hatch is the easiest to imagine.
Of course most of Pool Day is absolute frantic melee mayhem with blind disregard to any strategy or positioning. But every now and then it gets one-sided if the other team is really good, and they spawn camp the other team. For this I think a defensive nook (with a spawn point in it), or another toilet or some cleaning closet in the back of the base spawn area would make sense.
Anyway, I am sure I get flamed for this because that is the nature of internet, but whatever.