Thank you
Something is up if it's set to 60 fps but only getting 30, especially on the map screen.
The gpu usage and overall performance is lower on the map screen because most objects are beyond the view distance at that height, which is why the view distance setting has such a large effect on fps when the map is closed.
Is your gpu software capping your global framerate at 30?
I must also reiterate that if you are holding a relatively steady fps while gpu usage fluctuates, that's great. High gpu usage isn't necessarily a bad thing if the framerate stays steady. It just means there's a lot of things to draw on the screen. Fps is the primary concern.
It would also be good to set everything to maximum and then check how view distance effects fps.
You should get better fps with everything set to maximum with the lowest view distance than everything set to low with the highest view distance. Although something else is capping your fps at 30 and the lowest it dropped is 29 so not much can be gleaned unless we figure out why your fps is capped.