Looks like the finger-tracking of the screen is still stuck at a lower rate that is less than the improved FPS.
So when you drag the screen with your finger constantly touching the screen, the screen is still pretty jerky and doesn't really track smoothly when you scroll.
But to really see the smooth effect of the FPS uncap when scrolling, drag and "flick" (lift your finger off the screen) so you release the screen and watch it scroll by itself using inertia - buttery smooth. If you don't finger your screen, it scrolls smoothly.
So dragging the screen to scroll with your finger in constant contact is a real "drag" on the FPS

Better to flick-scroll by relying on the inertia to do buttery smooth scrolling at max FPS.