@mrow_pizza worked on that change. It is a refactor of ScrollingFrame internals which should fix several known issues, and probably some more which weren’t known to us:

Scrollbars sometimes displaying in the wrong position.

Sometimes being able to scroll horizontally in a vertical-only scrolling frame.

AbsoluteWindowSize not firing changed events.

Incorrect clip rect when the scroll bar is set to the left side.

Flickering when switching tabs in the developer console.