I'm sure that those can quite easily be made to look "human-like."

"Respond within 4-12 hours."

"Do not respond between midnight and 6am EST." (Or CET, whatever makes sense.)

Right now the most obvious traits are the well-known ones that are hard for most LLMs to shake off. Em-dashes, word choices, and the very limited ways in which they structure sentences. Terseness and conciseness is also a tell, which sucks.