Which Flag State would you write to re: Rule 20? What would you tell them, or ask them?
Maybe you can ask them to ensure that it is possible to tell a Cruise ship’s “pretty lights” and movie screens from their Navlight. That would at least make some sense.
Maybe you could better post your opinion in threads about shore leave and mental health of seafarers, which also exists on this forum. Like this one for a start: Merchant Mariner Shore Leave