Pressure in lager tank

[enohcs]

I'm lagering in corney kegs. I just got my latest issue of zymurgy and it has a very good article from the founder of Gordon biersch and he's saying that the lager tanks should be maintained at 9psi. Considering the source I'm about to go add pressure to the tanks, no questions asked.
Do others here use or not use pressure when lagering?

 

[Darwin18]

Why not carbonate while lagering?

 

[Ender]

Yeah, that's what I do.