since you are running manual I would think your culprit is the single black vs multi-black. The multi-black was likely creating pooling and making your dots 'bigger' due to the pool spreading. You may have also been unknowingly underexposing with the old unit and making the dots bigger as well.
if you can compare a 'before' upgrade screen & film and after, you should be able to see this with a loupe.
depending on how hard you're pushing, the rubber tops could cause a bit of gain due to them being soft, but I really think that your problems are in the screen, and not at press.
-J