UIActivity is not annotated with concurrency information. Does anyone know if subclasses you create will always run on the @MainActor ?

I'm seeing a lot of unexpected CPU usage when running the iOS 26.1 simulator. Looks like a "MercuryPosterExtension" is crashing over and over, which then causes the "ReportCrash" process to run, presumably to create the crash report. Doesn't happen on device, nor on iOS 26.0 simulator. I suspect MercuryPoster is related to wallpaper. I also don't see any wallpaper background in my simulator. Few lines from the stack trace: Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 libxpc.dylib 0x18011defc _xpc_api_misuse + 88 1 libxpc.dylib 0x18012e16c _xpc_shmem_create_with_prot.cold.1 + 24 2 libxpc.dylib 0x180113a70 _xpc_shmem_create_with_prot + 276 3 MTLSimDriver 0x23795ed48 -[MTLSimDevice newBufferWithLength:options:pointer:copyBytes:deallocator:] + 260 4 MercuryPosterExtension 0x10081d21c 0x100758000 + 807452 13 PosterKit 0x240d003d8 -[PRRenderer scene:willConnectToSession:options:] + 648 14 UIKitCore 0x1856bcf18 +[UIScene _sceneForFBSScene:create:withSession:connectionOptions:] + 956

I'm building and running from Xcode 26 to macOS 15.5. On launch, app crashes on start dynamic runtime linking with failure to find _LocationEssentials framework.

For example: I have a list of to-dos, each with a unique id (a GUID). I want to feed them to the LLM model and have the model rewrite the items so they start with an action verb. I'd like to get them back and identify which rewritten item corresponds to which original item. I obviously can't compare the text, as it has changed. I've tried passing the original GUIDs in with each to-do, but the extra GUID characters pollutes the input and confuses the model. I've tried numbering them in order and adding an originalSortOrder field to my generable type, but it doesn't work reliably. Any suggestions? I could do them one at a time, but I also have a use case where I'm asking for them to be organized in sections, and while I've instructed the model not to rename anything, it still happens. It's just all very nondeterministic.

The speaker mentions there is "less risk of creating a retain cycle in when capturing self in a closure within a value type", such as a SwiftUI view struct. Can you elaborate on when this could actually occur? Thanks!