OpenCL is not a public framework on iOS. Furthermore, it's deprecated on both macOS and iOS.

Apple isn't pulling WebView. It's removing UIWebView. The replacement is WKWebView, which works more or less the same with a few different features.

Because for example in Pages the Page Format changes the document pages size. It's a document wide setting, and it's not used only when printing.

I hit the same issue in HandBrake (a sandboxed video transcoding app). Fortunately I need at most a few xpc istances, so I packed 4 separate xpc services (~ 80 KB each, linked to a framework to avoid duplicating most of the binary).I'll fill an enhancement request too.

Download the full macOS 10.15 installer from the App Store and install it.

Compatibility with previous iOS versions is managed by the deplyoment target. The iOS 13 SDK doesn't prevent an app from running on a previous iOS version.

Writing inside the app bundle invalidates the code signature, so the next time macOS will check if the code signature is valid, your app won't work anymore. You should write the configurations in ~/Library/Application Support/<name of your app>/ or something similar.Your app is being run from a read-only place probably because of "App Translocation" security feature.

Download the full install from the App Store and reinstall it.

Yes, app translocation will run the app from a read only path until you copy the app somewhere else. A solution to your issue would be to bundle the data inside your app, and read it from the app bundle if it doesn't need to be modifed. Or ask the user where to write that data if your data needs to be modified.Another solution is to sign the .dmg file too, that should avoid app translocation if I remember correctly.

A XPC service is not a stand-alone app, it needs to be launched by someone else is a specific way. Either by directly by launchd, or as a result of a request by an app.

You either get Zoom to rework their SDK to work inside the sandbox, or you ship the app outside the sandbox. Apple surely won't give you an exception.

Do you have a display connected to the eGPU, or are you using the internal display? macOS never uses an eGPU for the internal display. An app can use it, or you can force an app to use the eGPU, but you can't use the eGPU for all the things on the internal display.

There is a new preference option to enable/disable the boot chime in System Preferences (can't remember where) even on newer Macs.

You can add an accessory view to a open/save panel. It's a public API, but you have to made the view yourself.

You can restore the T2: https ://mrmacintosh.com/how-to-restore-bridgeos-on-a-t2-mac-how-to-put-a-mac-into-dfu-mode/