There are a couple of different beliefs about the fps cap in TF2, I don't think there is much of a benefit from running the fps cap at 2x refresh rate + 1 since your fps will probably dip under that even with an fps config.
Some people also run at 132 fps for the following reason:
Originally Posted by Chris FPS config
// This FPS cap should *always* be set to a value higher than `cl_cmdrate' in
// any case, or the discrepancy between clientside frame generation and frames
// to be sent to the server will no doubt cause you many a headache, especially
// when it comes down to hit registration. Other than that, I recommend
// for everyone to use the value `132' (2*66), as long as you can generally
// keep that value stable without regular drops.
People will also run 132fps if they're running acceleration which is fps dependent like Quake. I personally find that running "fps_max x" causes input lag and jittering, but YMMV.
I don't really have much knowledge on 120hz panels so I'll reserve any comments for someone that actually knows what they're talking about.