See, clear as mud. It appears that the wrong interpretation at Skippers meant any line Captain could allow ICUS by the FO when they have changed their tune now to only training captains supervising FO whilst logging ICUS.
Yes the seat does not matter, in command does not mean manipulating pilot. A long haul Captain on a 747 who goes down the back for a sleep is still in command of the aircraft whilst not even on the flight deck!