Looking at an iOS native Scrollview (e.g. Safari or Mailbox in Mail) in landscape on an iPhone Xs you will see the following behavior:

• When the notch is on the left, the scrollbar is drawn all the way at the right edge of the screen (the content of the scrollview does not go all the way to the right to avoid potential obtrusion by the round corners)
• When the notch is on the right, the scrollbar is not drawn all the way to the right and instead slightly indented (just like the content) to avoid the notch

I believe I cannot easily replicate this behavior with the Safearea and Scrollbar widget in Flutter. Either the scrollbar is always (regardless of notch orientation) drawn with a padding from the edge of the screen (and would avoid the notch if the phone is orientated to have the notch on the right) or the scrollbar is always drawn all the way at the screen edge (and thus obstructed by the notch if it happened to be on the right side).