https://www.bleepingcomputer.com/news/microsoft/microsoft-improves-windows-10-defrag-adds-theme-aware-splash-screens/

Microsoft has improved the defrag experience and introduced theme-aware app splash screens with the release of Windows 10 Insider Preview Build 20241, the latest Windows build available for Windows Insiders in the Dev Channel.

Insiders in the Dev channel who wish to upgrade to the latest Windows 10 build can go into Windows Update and check for new updates.