SwiftUI ForEach .onInsert not called for outside drags?

Hello, I'm trying to accept drags from outside my app to create a new row in a list.

I've observed .onInsert not getting called in this scenario and I'm curious if it's 100% not possible, or if there's an obscure view modifier that I am missing.

Thank you.

struct ContentView: View {
    @State var data = ["One", "Two", "Three"]
    
    var body: some View {
        HStack {
            List {
                ForEach(data, id: \.self) { item in
                    Text(item)
                }
                .onMove(perform: { indices, newOffset in
                    data.move(fromOffsets: indices, toOffset: newOffset)
                })
                .onInsert(of: [UTType.plainText], perform: { index, items in
                    // WORKS
                    data.insert("new", at: index)
                })
                .onInsert(of: [UTType.data], perform: { index, items in
                    // Never called
                    data.insert("OUTSIDE", at: index)
                })
            }
            
            Text("DragMe")
                .onDrag {
                    return NSItemProvider(item: "DragMe" as NSString, typeIdentifier: UTType.plainText.identifier)
                }
        }
    }
}