I got stuck while writing this in a post
"It is you who does not want ...."
While the third person 'it' takes 'does not', when I reveal that it is 'you', should I use 'don't'?
In my final version, it's 'does not'.
The dominant subject here is the pronoun "who." Third person. To complicate matters even further, consider this (a notch more natural sounding than your example):
Are you the one who does not wish to ...
Pretty cool, isn't it?