The aircraft we currently operate are certified for 2 crew, not 1. Taking controlled rest is operating the aircraft outside its certification.
The need for controlled rest is more often than not a by-product of the way we are rostered. Back when we flew to 700 hours rather than 900 I never felt the need for controlled rest.
It really pisses me off when someone takes controlled rest and then doesn't report it. If fatigue isn't a problem as far as the company and regulator are concerned things will only get worse. With the new controlled rest report form it doesn't take long. If everyone reported when they actually took controlled rest HKCAD would realise how badly CX addresses fatigue.
CX does a piss poor job of educating new joiners on fatigue management. I had to do my own research to learn what works best for me. I paid for my own copy of CrewAlertPro to assist with my sleep management.
If you take controlled rest REPORT IT.