To just screw up the discussion even more, my example with the IS-2 did not involve the "hull-down" command. As an old CMBO'er, I still like to place them myself. And once it was there, I had a clear line of sight to the point, in front of it, in back of it, to the left and to the right of it, with no obstructed lines of sight reported for multiple yards around. And still the ditch digging effect.
If this is an intentional part of the game, why doesn't the LOS indicator line report "Main Gun Blocked" like it does for the bow MG when that is the case?
And just a suggestion to anybody to whom it might apply: probably a good idea to edit any messages that contain derogatory slang terms for female genitalia before somebody bigger, badder and balder comes along and "edits" the poster.