There are no optional Features to configure in WinRE, which is why it was skipped. Recovery Environment is a limited version of Windows, similar to WinPE, which allows you to perform some basic troubleshooting and recovery steps.
Only the normal Windows image has optional Features which can be enabled or disabled.
WinPE and WinRE both allow adding Optional Components (OC's) from the Windows ADK, but those are Update packages. Otherwise there are no Features by design.