It will not work From my last testing ( By license) I give it a try maybe it will *** on IoT Ltsc 2021
[About Sandbox] Feature name: Containers-DisposableClientVM Package name: Containers-OptionalFeature-DisposableClientVM-Package~31bf3856ad364e35~amd64~~10.0.19041.XXXX (depending on CU build) So, check product policy "Microsoft-Windows-Sandbox-Enabled". If 1, enable\disable Feature Containers-DisposableClientVM (no need to install\uninstall package). If 0, it's useless no matter how.