Thanks for starting a great thread.

Not that I have crazy BDSM fantasies these days, but think I'm more like you in this example than your client. I'm more prone to thinking about how the fantasy won't work than being revved about how it could. For example, there are a couple of UK mistresses who do something called The Kidnap Klub, which is abduction role play with a kind of espionage twist. They seem great, the concept seems very cool, but when I think it through, I worry I couldn't stay in the headspace for all the time required.

That's probably the remaining fantasy -- to do a scene like that or some kind of extended prison-themed scene. Maybe not OWK-levels of severity but something where I'd have to accept the length and settle into an extended submissive headspace.