X1 Producer Expanded Pro Channel Documentation

Non-existent. Selecting the PC4K Expander/Gate or the Saturation Knob and pressing F1 leads to the general Pro Channel documentation which has all of one sentence about each one. I did find a Cakewalk TV video about the Expander/Gate, but it says the Range knob is "standard", whatever that means. It appears to define the range in dB between threshold and zero dB, but I'm not sure. The documentation at the Softube site has more than one plug-in with a saturation knob, so I assume this one is from the Focusing Equalizer. At least the Softube documentation is entertaining. For example:

Saturation Type With keep low you will be able to distort the track without getting a farty bass sound. Keep high will do the same, but for high frequency material. Neutral will not do anything special with either the high or low frequencies.

So, specific questions: 1) What does the range knob on the Expander/Gate really control? 2) Why do we now have 2 tube saturation modules in Pro Channel?

Thanks.  I agree that this is a downward expander only.  The statement in the documentation
 

An Expander can be used to reverse the effects of a compressor or to add further dynamic range to a performance. Now you can add variable volume back into a performance that has been overly compressed or just performed without enough expression. Add life to vocal tracks, put punch back into drums and drum loops and so much more.

 
is just another one of these urban myths that get passed around by people who don't understand expansion.

In Gate mode, it completely silences any part of the signal that is below the Threshold. In Expansion mode, it progressively lowers the level of signals below the Threshold so that the dynamic range between the softest parts and the loudest parts is expanded.