From the design documentation for the iOS sheet, it is recommended to add drag handles, or a grabber, to the top of the sheet when the sheet can be resized. This can be done through presentationDragIndicator in SwiftUI, or prefersGrabberVisible in UIKit.

Related issue is the one to add detents, or the ability to resize the sheet by dragging #169832.

This proposal is to add a boolean property to CupertinoSheetRoute that would display a native looking drag handle at the top of the sheet. This drag handle would have SemanticsRole.dragHandle applied to it as well.