Mfilos made a custom Auto AGA/RTG switch on his Amiga 4000. He wanted to use the manual switch from Ratte's Auto AGA/RTG switch. But he wanted a nicer switch on the place where the keyboard lock switch is located. A small pcb with a CD 4017 IC, two relays and a couple of small components is now built into the A4000. You can read all about this project on the blog from Mfilos.