My answer comes from another direction to where this discussion might go. I've been in the printing business for quite a few years and grew up with the photographic gadget fever prior to my adult professional life. This is to say I've had to own a lot of gadgets in my day. I say HAD to own only because soon enough it just became more junk in my way. Is there no reason to be satisfied with just the developing tank and using your customary temperature-stabilizing methods, and just forget about trying to set up a production about it? So I say, unless you're needing to ge into some sort of production, be GLAD that you're good enough not to need all that junk, which will certainly become something else in the way collecting dust. I don't say all this to be contrary. The viewpoint is from a guy who would LOVE to get rid of all this printing junk and machinery, and never see another one again. Other than that I think you're just looking to have a streaky-film situation that you'll never satisfactorily remedy.