The confusion was simply about possibilities implied by the term immobile as a designation for a vessel that can move. What did that mean regarding a vessel with a weapon that can only be targeted at "immobile" vessels. Does the shadow cloud lose that designation if it moves or is it a kind of designation because of the nature of the vessel etc. Like the minor linguistic difference, which means a lot in rule terms, between things that effect a "Heavy Tank Company" vs a "Guards Heavy tank company" in flames of war etc.
The question came up whether the rules could be interpreted that way so why not put it up on the forum to find out how legit it was.