I have had to go through mm-wave scanners in MIA and MCO. I am sure I could have opted out if I were willing to go through the process of explaining things to the TSA employee instead of just rushing through.

I am in both because I enrolled in TSA Pre and then about a year later needed to be in Global Entry due to a sharp increase in international travel. Once my TSA Pre expires, I don't expect to have both. Right now, various frequent flyer programs still have my TSA Pre number entered and I just leave it alone.