Using the middle mouse to scroll a scrollbar doesn't seem to emit interactions (unlike manually dragging, which does). Is this intentional? I can see this being a mistake since Android doesn't have to handle middle mouse scroll as far as I understand?

Is this intentional

Yes, when we scroll the list, we don’t interact with the scrollbar. We don’t hover/press/drag it. Scrollbar just changes its position in response to the changed scroll position in the scrollable list. What are you trying to implement?