I have been attempting to do the same thing but am also stuck.
I have an image and some text at the top of the screen with a list underneath. All of this is embedded inside a ScrollView. Using GeometryReader lets the list look as it would do normally but now I have 2 separate views that scroll independently.
.disabled(true) resolves the UI issues but removes the functionally of the list which contains NavigationLinks and DisclosureGroups.