Can I use my I-station V-module to control Matrix input/output levels rather than just crosspoints
Yes using the V-1400 (this product was discontinued from 2009) and ECS V5.1.3 you can set the rotary pot on the V-1400 to control the Eclipse matrix  input / output levels
Connect the V-1400 to the host I-station panel as per normalIn ECS 

• Declare that the V-1400 panel is connected to the host I-station panel in the matrix hardware  > advance settings tab. 

• Go to Panel programming and program a talk or listen label for the matrix port that you wish to control on the main I-station key (this would normally be on the top row of keys) as the first V-1400 panel connected to a I-station will automatically align its pots to the top row of keys. 

• Double click on the programmed I-station to allow ECS to show the "Key specific functions" box in the bottom right hand corner of the screen to appear.

• Select the key specific function tab and in the lower half of the screen- select input or output mode from the "Level Adjustment Applies to" 

• Complete the programming by making a download with RED reset.