...what would be the norms for encountering a recognised SP out and about?
It's an interesting question. 10-15 years ago I would baulk at the suggestion of sex work being sociality acceptable but times are a changing, When you consider sites like onlyfans and SA, the trend is towards more girls (and guys presumably) offering some sort of paid for sexual gratification. It won't become acceptable in my lifetime though so I'll keep my punting phone and my head down.
Still, I'd expect SPs would be treated like most other trade/service providers and would sit somewhere on the social pecking order, somewhere in the beauty and health category. I would say hi to the girl who occasionally gives me legit sports massage but I wouldn't linger and certainly not if she was with company. I went out with a beauty therapist once and on more than one occasion random blokes (clients) would come up and say hello. My compass would need realignment if I went out with an SP and I was fine with random blokes saying "hi, babe" in the supermarket aisles.
If I saw a reg on the street, I'd probably also say hello, maybe have a quick chat, maybe a flirt and leave with a promise of booking. I wouldn't have qualms about asking them for a coffee or a drink depending on the time of day, but the lines between servicer provider and social acquaintance become blurred. If someone I recognise but didn't know but wanted to see, I might go introduce myself.
All that said, would many SPs off the clock want to be bothered? I doubt it.
Of course one upside (depending on your POV) is that we'll see a host of trashy reality programmes where amateur girls go head-to-head (fnarrr) with pro-hos with porn star judges. Rather than go on Strictly or Bake Off, celebs and politicians in the autumn of their careers will put for the public.
Which celebrity boner is behind glory hole A?