Krusty I'm hearing you! I don't believe the regulators of the world originally came up with the concept of logging ICUS in order that airlines could get pilots log books upto the (a) the regs requirements and (b) the company's AOC reqs.
Are Captains aware that FOs are logging ICUS from the RHS while they are PIC? Or are these Captains designated company Supervisory Pilots? Either way it totally goes against the principles of ICUS being an opportunity for a less experienced pilot to gain some valuable time in the 'command seat' ie LHS.