To test your app on Windows 11 25H2, you’ll need access to the latest ISO image of that version. As of now, Microsoft typically releases Windows 11 feature updates through Windows Update, but ISO images are also available for download.
Since your machine is not officially supported, installing Windows 11 25H2 on unsupported PC might encounter issues. You might need to bypass certain compatibility checks, similar to your previous registry modifications. For testing purposes, you could also set up a virtual machine (using Hyper-V, VMware, or VirtualBox) with the Windows 11 25H2 ISO, which provides a safer environment for testing.