The Zoom function of your mod seems to break when, from the component design screen, you go Menu > New (Ctrl+N), or edit a part from Menu > Library (Ctrl+L) > Edit. It fixes itself when you quit to main and reload a project.
Additionally, when first opening a project, you can only pan the component design screen left or right, but when you choose to make a new chip or edit an existing chip, you gain the ability to pan in all directions.