You can post all the pictures in the world, it won't give you an answer. When I doubt about skin conditions, I don't engage, change the activity, add protection, or terminate the appointment.
Only doctors could confirm something like this. Your fears shouldn't be used to blame or accuse others for something that might be innocuous.
You can't control what others do, the only thing you can control is the level of protection you use and your tolerance to the risk. The only way to know...
And there's no such thing as "refusal to screen" as we always screen one way or another. They just don't know what's important for each of us, but screening is an ongoing process.
As if a booker can't go rogue and steal the client list to shake down every one on it.
There are independents, and there are scammers. We don't belong in the same catogery. Don't blame the honest, hard workers if you fell on scammers on a shady site, it's not warranted.