Simple suggestion really. Can there be a "Copy Dialog" function? The reason is because an installer with customized dialogs can be difficult to expand using the current New/Add Dialog function. It only adds a dialog with its default values, which can prove difficult to change depending on how much customization you added to your other dialogs. It'd be much easier to copy a dialog over and change what is already existent
This is already on our TODO list and it will be available in a future version. I increased its priority. In the meantime, you can select all controls on a dialog, use copy function and then paste them on a new dialog.