Interesting thread. Here's a link to the late Carl Arendt's micro-layout site. It's now run by a Dutch gentleman, and the archive is a treasure trove of switching layout ideas in all scales.
https://www.carendt.com/micro-layout-design-gallery/
https://www.carendt.com/catego...ll-layout-scrapbook/
O scale 2-rail shelf switcher here: https://www.carendt.com/small-...k/page-97a-may-2010/