He requires? Any girl who has been around for even a bit of time would never do this. Any good client like myself would never ask a girl for a free meetup. Your time is valuable, people like him are just there to waste it.
The longer the encounter the better. I cant see how a 15 or 30M encounter could be anything memorable as there is no time.
1.5 -2H atleast for a proper introduction.
I might be used to the USA scene where longer dates are the norm.