When I placed the *.simruntime packages in /Library/Developer/CoreSimulator/Profiles/Runtimes the Finder would not stop repeatedly complaining. “xrOS 1.0.simruntime” cannot be opened because the developer cannot be verified. To silence that, I ran sudo xattr -r -d com.apple.quarantine on each package. When launching Xcode for the first time the runtimes that I already downloaded and copied to /Library/Developer/CoreSimulator/Profiles/Runtimes were listed as «Downloading», the Downloads window in Xcode had no entries, and even though I could pick Simulators for iOS 17.0 and visionOS 1.0, I could not run them. After deleting the packages in /Library/Developer/CoreSimulator/Profiles/Runtimes, I decided to get the runtimes using Xcode -> Preferences… -> Platforms. Now I have a /Library/Developer/CoreSimulator/Volumes directory with mounted disk images inside them and the .dmg files live in /Library/Developer/CoreSimulator/Images. There’s also a binary property list at /Library/Developer/CoreSimulator/Images/images.plist that seems vital. Enough time wasted, visionOS waits for me. :)