Is fever a symptom of glycine deficiency?

A 2022 LessWrong post on orexin and the quest for waking hours argues that orexin agonists could safely reduce human sleep needs, pointing to short-sleeper gene mutations that increase orexin production and to cavefish that evolved heightened orexin sensitivity alongside an 80% reduction in sleep. Several commenters discussed clinical trials, embryo selection, and the evolutionary puzzle of why short-sleeper genes haven't spread. I thought the whole approach was backwards, and left a comment: Orexin is a signal about energy metabolism. Unless the signaling system itself is broken (e.g.