Ah, I think this is what I was thinking of: https://developer.mozilla.org/en-US/docs/Web/JavaScript/The_performance_hazards_of_prototype_mutation https://develo

Ah, I think this is what I was thinking of: https://developer.mozilla.org/en-US/docs/Web/JavaScript/The_performance_hazards_of_prototype_mutation https://developer.mozilla.org/en-US/docs/Web/JavaScript/The_... It seems this only pertains specifically to overwriting the __proto__ of an existing object (the is the prototype of other things).