before I started being openly transgender... I never got that "randomly selected extra screening" not even after my surgery which had me on crutches.

now... I always get that random screening. every time. and my legs are a bit bowed. so they always bitch about my legs not being perfectly straight even when I'm wearing shorts and they can see my knees. and the white dust that I always pick up leaning against airport walls... is always magically drugs even when the dog doesn't react.

I empathize and if that's the way you feel, that's understandable.

But I'd recommend to try it, even if your feelings suggest it's just going to make trouble. As noted, there is an explicit non-discretionary optional policy for it and TSA agents - even if they're trying to make the photo seem like the only choice - get a ton of opt-outs every day and it's probably not going to (for the moment) trigger retribution. (I say this traveling with non-white people and never seeing them get secondarily screened later in the process, or more so than me anyway - but yes, I'm speaking from a place of privilege so could be wrong.)