AppContext based switches to disable functionality, controllable through also in the host application through AppContext or by configuration with AppContextSwitchOverride. https://docs.microsoft.com/en-us/dotnet/framework/configure-apps/file-schema/runtime/appcontextswitchoverrides-element

Since AppContext is not supported on.NET Framework 4.0, a local implementation is used there instead, which cannot be controlled though configuration or through AppContext.