According to https://doc.qt.io/qt-6/qml-qtquick-dialogs-filedialog.html#options-prop, attempting to select an existing file for saving should produce a confirmation prompt about overwriting the file.

However, this is not the case for the non-native dialog.

Code

import QtQuick
import QtQuick.Dialogs

Window {
    width: 640
    height: 480
    visible: true

    FileDialog {
        id: dlg
        fileMode: FileDialog.SaveFile
        options: FileDialog.DontUseNativeDialog
        onAccepted: console.log("Selected", selectedFile)
    }
    Component.onCompleted: dlg.open()
}

Expected outcomes
When you select an existing file, you'll be prompted about overwriting it. This behaviour occurs with the native Windows dialog.

Actual outcomes
When you select an existing file, no confirmation is requested.