Setting the Stretch Text checkbox enables the Stretch Text button.

Pushing the button "Set Prompts For Stretch"  prepares the existing settings in your template for using the new display.  It tells you in the box what will be changed.

You can easily return to older settings by unchecking the Stretch Text box, and resetting your Justification, Right border, moveable border to earlier settings.

Icons are not affected in the vertical mode of stretching text.