Apparently game don't support exclusive fullscreen and in borderless window, suffer from noteven frame pacing. Despite 60 fps lock seems to be solid, traversing world causes hitching and micro stutter. Investigating game with graph provided by RSS shows spikes in frame pacing, they are very short but persist in regular intervals giving feeling of hitching.

Here is how it looks when all option are turn ON with V-sync:


with V-sync OFF:


With FXAA instead SMAA:


And 720, with everything turn OFF:


Even menu suffer from this:


Like you can see, in every case frame pacing is bad, no matter of settings and resolution, for some reason it even worse with FXAA. Choosing DX9 don't change nothing.

Solution is simple, game need external lock. Apparently in game setting is broken and it's only turn off 30 fps cap, and v-sync wont do his job properly. I propose in driver lock (RSS should also work) and i will show it in radeon software. Find game (if necessary add *.exe) turn on Chill and change his max and min setting to 60:

As you here scrool down where you can also force 16 x AF to improve texture filtering:

Its done. Boot game and enjoy even frame pacing and fluid gameplay: