Settings that actually cost you frames (and the three that don't)

I measured frame times, not average FPS. Averages are the reason people keep turning off settings that cost them nothing while leaving on the one that is causing their stutter.

Three settings are effectively free on anything modern — turning them down buys you under two percent and makes the game look noticeably worse. They are the first three rows in the table.

The expensive one is the volumetric setting, and it is expensive in a way that averages hide completely: it does not lower your average much, it just produces a spike every time you enter certain weather. That spike is what you are feeling.

Confirmed on a completely different configuration. Dropped that one setting a notch and the traversal stutter I have been chasing for a week is gone. Average barely moved, which is exactly your point.