Unlike you, I don’t have any doubts nor do I have doubts about your doubt. I have read many of King Tarzan’s reviews and he gets DFK most of the time, even from girls that do it at their discretion.
I presume he's usually fairly careful about who he chooses and even though he might get DFK most of the time, he definitely doesn't get it anywhere near all the time. He started his "£20 kiss test" for a reason! As for girls who put FK at discretion vs just FK - in my experience that doesn't mean all that much. If they don't say at discretion then it does make proper DFK more likely but not all that much or at least not as much as you might think.
I guess, Mr. Tarzan must be a handsome muscular hunk. I believe DFK depends on chemistry and girls prefer the good looking guys when it comes to kissing, even though they don’t admit it and instead emphasize it on dental hygiene and fresh breath. I am old and ugly and I rarely get girls to kiss me, even those that are known for kissing. I have excellent dental hygiene and am a non-smoker, so DFK depends on one’s looks.
I presume you're being sarcastic about King Tarzan? From the posts I've read from KT himself he definitely doesn't sound good looking and certainly not a "handsome muscular hunk". I'm pretty sure he's even said that he gets no or very very little sex outside of punting.
Also, based on your logic, the numerous punters on here who've received DFK are good looking or at least not old but that certainly won't be the case with all of them, there will be many exceptions.
I rarely get girls to kiss me, even those that are known for kissing.
Please review these girls, particularly those who are "known for kissing" but let you down.