I am developing AirZcreen Desktop, a free macOS app that creates an independent extended display in the current user's Mac desktop session and streams only that display to one paired browser on the local network. The required behavior is a real extra macOS display onto which the user can move windows from other apps. The app must not capture, mirror, reconfigure, or make changes to existing physical displays. ScreenCaptureKit handles capture after the owned display exists. There are no user accounts, audio capture, or remote keyboard/mouse controls. Our prototype uses CGVirtualDisplay, CGVirtualDisplayDescriptor, CGVirtualDisplayMode, and CGVirtualDisplaySettings through Objective-C runtime lookup. These interfaces are absent from the public CoreGraphics headers in our installed macOS 26.2 SDK. We understand that App Review guideline 2.5.1 requires public APIs. We are seeking a supported replacement, not assistance using undocumented interfaces. A bundled helper owns the display and its cleanup, including parent-pipe closure and heartbeat timeout. An isolated App Sandbox build can create the display, capture it, stream it to Chrome, and remove it on normal Stop. This runtime result does not establish App Store eligibility. No build has been submitted for review. Is there a documented public API for a third-party sandboxed macOS app to create this kind of independent host display? If so, which framework, minimum macOS version, entitlements, and helper-process model should we use? If this capability is not currently available through public APIs, what is the appropriate way to file a request for it? The PGDisplay documentation describes a display for a guest operating system in a virtual machine, which does not provide the host-desktop behavior we need. I have not found a host-display creation API in the ScreenCaptureKit documentation. References: https://developer.apple.com/app-store/review/guidelines/#software-requirements https://developer.apple.com/documentation/paravirtualizedgraphics/pgdisplay https://developer.apple.com/documentation/screencapturekit