Massive improvement! I still find the controls with mouse + keyboard a little finicky—especially changing the polarity. I often found myself getting lost between clicking and E, and also found it very annoying that I couldn't change polarity with the mouse. Maybe a middle click? Or scroll? That way with two scroll "notches" it would go from red to blue to red.
I also wasn't sure if the lag between switching polarity was intentional. I couldn't figure out the last puzzle though in my brain part of it was polarity switching. Something to tweak maybe.