The regulators are faced with 2 levels of solutions to help prevent this from happening again. Improvement such as lit exit signs, proper charging stations and more effective smoke detection would be relatively inexpensive and easy for operators to comply with. Significant improvements like reducing the number of passenger berths and reconfiguring escape routes would be a financial burden for the operators and the CG appears to be sensitive to the economic impact of their decisions.
The one item on the COI that most likely would have prevented this tragedy is one they can’t enforce: The directive to maintain a night watch while the passengers are asleep.