No answer if and where it is written. Probably all agree that 8' is not a good number to aim for - that would be the front edge of the 150 m marker.
But 35 rings a bell, right, screen height is common knowledge. As a careful and safe compromise between economy and exposure to risk, under wet or contaminated conditions, 15 feet is the regulatory minimum.
I like that. One should never aim for closer than what gives 15 feet wheel clearance at threshold. That margin shall be sacred in the aiming phase.
Skilled ones who trust the performance might still aim for 330 mtrs and shorten the flare to land there.
Those who touch at 500 mtrs casually better adopt the short aim technique.
95 % of us in reality struggle somewhere in between, despite the different perceptions of own heroism.