I'm not sure a complex mechanical device is a requirement. The airlines could mention before takeoff that it's proper etiquette to not fully recline your seat u

I'm not sure a complex mechanical device is a requirement. The airlines could mention before takeoff that it's proper etiquette to not fully recline your seat until after the meal waste has been collected and to not recline during service. This doesn't physically stop someone from reclining but it certainly sets a social expectation of them and empowers a flight attendant to respectfully ask the patron to decline their seat when it is inappropriately reclined.