Any new features for 4.21? 
Some warnings shown when packaging in 4.21:
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_FogColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_StarsColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_MoonColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_SunColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_CloudsSecondaryColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_CloudsBackgrundColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_CloudsLowerColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_CloudsUpperColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_SkyLowerColor
UATHelper: Packaging (Windows (64-bit)): LogInit: Display: LoadErrors: Warning: Linear color curves now accurately handle RGB values > 1. If you were relying on HSV clamping, please update C_SkyUpperColor