If your drag the cursor all the way to the bottom hard enough the dock will show, then you will return to the home screen. This works with the original magic trackpad. Also interestingly enough I connected my Logitech mouse with the dongle to a camera connection kit and everything works, scrolling right clicking etc. It‘s better than the magic trackpadyes, but only with activated assistive touch. i could do that before, so this new mouse feature just makes it worse, you still can’t use the mouse without assistive touch, so i wonder why they present this now as a new feature, when it isn’t possible to get to the home screen without additional steps.