ASR-Fs and AFTLS fail massively on the same point. They look at the most current duty, while a duty maybe tiring in isolation, nothing is done to look at the fatigue that the buildup of multiple tiring patterns have.
The failure from a scientific point on ASR-Fs is the data is being collected to look at the single last duty, when the data should rather be looking at the the combination of duties. If a duty comes up regularly on ASR-Fs, why isn't a group of pilots given that duty following say 72 hours rest to see if they also result in an ASR-F.
Our industry is so far behind the rest of the world. In many parts of the world employers who have shift workers have published tools via apps or websites where multiple shifts are looked at, and they will tell you if necessary to tell the duty manager the system says I must be fatigued, find me a replacement.
Talk to any sleep expert, the alternating day/night shifts we do are extremely dangerous. The scientific data shows human performance will be worse than someone that is legally drunk.
In our industry, we have call in sick, when we are not sick, we are fatigued. Some airlines even take away pay or holidays for being fatigued at the company's behest.