If you still own the Yezz Billy 4.7, you're now free to install Windows 10 Mobile Insider Preview builds on it. The Windows Device Recovery Tool was recently updated to support the device.
Build 22000.829 (KB5015882)
Windows 11 in Release Preview adds urgent notifications bypass and more
windows 11 insider preview
Windows 11 released to Dev Channel and ISO comes with File Explorer tabs
windows 11 promo