Auto smooth not available

HI Paul,

Shade Smooth by Angle is more or less the same as Auto Smooth, but you'll have to adjust the Angle immediately after Shade Auto Smooth (Adjust Last Operation Panel, also available with F9).

Or use the Modifier: Normals > Smooth by Angle.

Yes, but don't use the Shade Smooth By Angle option...
Use Shade Smooth and then add the Smooth by Angle modifier, this modifier basically replaces the auto smooth option that was in the data properties.

Shade Smooth By Angle adds sharp edges to the mesh. It's certainly not ideal IMO.

True Adrian! (The Modifier does that as well, but not destructively.)

In 4.2 this will probably be changed:

Shade Smooth by Angle will be removed. In its place will be Shade Auto Smooth (as it is called now, name may change) and that just adds a Shade Smooth by Angle Modifier to the Mesh.