What is EdgeSafeHostingExtensionEnabled about?

Hi Johannes Goerlich​ - I spoke with the team and got some answers!  😀 Hopefully this helps! 

Is this a regular browser extension? If so, what is the related Extension ID? 

It's a browser extension, "Edge Safe Hosting", ID is gkhmmbgolohbdhildkleckjhknljncph. Store Page

How does this combine with other extension management policies?

The feature does not supersede other extension policies; if the extension is required or blocked by policy that should still take effect.

Or is it a browser component, which should show up under edge://components? What would be its name?

The extension is treated as an "External Component" extension; it's considered a browser feature implemented using the extensions mechanism. It will not show up under edge://extensions but will show up under edge://extensions-internals.

What is the exact purpose of "Microsoft Edge Safe Hosting component" extension?

The extension is automatically installed, if it's not already present, when the user previews generated HTML/JS apps in Microsoft 365 Copilot. The extension is uninstalled if the user does not use this feature for 90 days.