The 'Born to DFK" T shirt now collects dust, as I have to move with the times. I find more clients will DFK these days, but tend to be a little apprehensive of tender LFK - maybe it's considered more personal - who knows - men tend to set whatever lines suit themselves and they feel comfortable with.
Here's the dealio given my limited experience.
I find that there are more clients these days who will DFK and in some cases YMMV apparently isn't so evident. The B tourists, although certainly not restricted to, would be a good example. However, YMMV does still apply in some cases and still others generally are known not to allow/enjoy kissing en francais.
There are clients that will indulge in LFK/DFK after a few repeat visits, but tend to be more of a YMMV kinda deal.
Then there are clients who are known not to DFK who just out of the blue will suprise you either early on, or upon repeat visits will become comfortable enough to explore if you continue to "test the waters" ...
I've heard it said that Asian clients tend to shy away from DFK - In my experience this isn't necessarily the case and it very much depends on the individual.
The bottom line is, it's not a standard, but it's also quite possible, especially if you attract clientele who are known to indulge to some degree.
Be sure to bring the 'cool mint listerine pocket paks' and mistletoe.
PS As a client, I wear the shirt hoping that one day some kind MPA might just take pity on me : (