That gap is about 2X where I calibrate mine. 105 is crazy high of a bed temp for pla. That is what I use for ABS. Ever though about getting some acrylic sheets from depot or lowes and enclosing that thing. I am a believer in a controlled environment for printing any material.

Glass rocks for a build platform and is cheap. The only issue I have had printing on it is if a print (ABS) sticks too well to it you can get the glass surface to pop a section out.