Well, they call it stage manager, but in iOS 18 (too) it only offers split screen and one window overlaid to the side. There is an example in the page somewhere.
You are correct. I would have sworn it was called Stage Manager in 17... For what it's worth, searching for "Stage Manager" in Settings returns only stuff in this multitasking page of settings.
All I’ve wanted is a pocket iOS device that I can dock and use for some desktop-like use cases. I had really hoped that the iPad mini would get stage manager for this reason. Oh well