Given a List with insetGrouped listStyle, how can I fill the contents of a Section such that no padding is visible?

In the follow example, I have a Rectangle overlaid with a Button. The Rectangle (in mint) is automatically inset within Section.

Problem: However, I want the Rectangle (or any content for that matter) to fill the entire space of the Section, instead of being inset. There should be no white padding around the mint rectangle.

Supplementary/fallback question: failing the ability to remove that inset from the Section, how can I mix and match my own views with an .insetGrouped List? e.g. to provide my own hero view, which won’t be subject to the Section‘s insetting behaviour?

(I’ve been having to use a ScrollView to do this so far, but that involves a lot of rebuilding default iOS behaviours/looks.)

struct InsetGroupTestView: View {
    var body: some View {
        List {
        
            // Content that requires no padding/inset within the Section.
            // i.e. needs to expand to fill the entire Section.
            
            Section("Foo") {
                Rectangle()
                    .foregroundStyle(.mint)
                    .frame(height: 100)
                    .overlay {
                        Button("Press me") { }
                            .buttonStyle(.borderedProminent)
                            .buttonBorderShape(.roundedRectangle)
                    }
            }
            .buttonStyle(.plain)  // Remove tap-highlighting from entire cell.
            
            // Content that needs system inset/padding.
                
            Section("Bar") {
                ForEach(1..<5) { index in
                    NavigationLink(destination: Text("Item #(index)")) {
                        Text("Item #(index)")
                    }
                }
            }
        }
        .listStyle(.insetGrouped)
        .navigationTitle("Inset Group Test")
        .navigationBarTitleDisplayMode(.inline)
        .scrollIndicators(.hidden)
    }
}
    
#Preview {
    NavigationStack {
        InsetGroupTestView()
    }
}