When your ear starts to hurt, the fluid is already building up. And most of the time it's not worth dealing with. I don't think making an impression every time my ear starts to get red and hot is realistic. (But then again, I am lazy!)
I personally don't care about the esthetics of cauliflower ear anymore, but I do drain the hematomas to relieve the pressure when I get a big one and it makes it hard to train. I had one last month that was huge and wouldn't stay down, I ended up having to get stitches in my ear.