Interesting you say that, after reading lots of reviews, no one seems to use the top or bottom screens, I never have and after stuck spares use loads of oat husks.I found that I can slightly reduce the BZ difference in temps by using rice hulls to aid the recirculation during the mash.
I've also ditched the malt pipe bottom screen, top screen and adjustable pipe for a bottom screen that has no hole in it ( 13.9US $ |Brewzilla 35L Bottom Screen for Malt Pipe (no overflow hole)|Beer Brewing| - AliExpress ) and I recirculate the wort directly onto the mash. Plus I always keep the lid on and use some tin foil to close the top. You do need to be careful about an overflow!
I also use a wort siphon spray on the end of the recirculation tube but they can be tricky to find. I've heard that some people have 3D printed them themselves.
Maybe all a bit too much but it's now part of my brew day process...
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Now you mention it that would make quite a difference to flow!