Unless I'm applying for some kind of CIA job or a freak is obsessed with me, who would take the time & pay money to find out things about me though a 20-year, 15-year background check?
An employer? Well, again unless I transitioned old (e.g, thirties, forties, fifties, sixties, YIKES!!) & had a lot of baggage when I did, maybe I'd be worried. But not everybody transitions so old & not everybody's got so much baggage on our backs. So for me it's the medical stuff that could out me.