It would be nice to be possible to link different designs, to create a better experience to test the user interface.
Hello and welcome to the forums!
Instead of using multiple designs, a better approach is to use pages - this will allow you to share CSS and other assets. You will also be able to create linked components, so that things like headers and footers are updated across your designs when you change them.
Do you mean that we need to export the pages then link pages on other text editors? I think he is asking to link the pages inside the app.