> First of all the discussion at hand is not the language implementation, the discussion at hand is about the language specification. TCO is a implementation feature, whether the engine/compiler/interpreter implements said feature is irrelevant to the conversation which is about the specification NOT the implementation. So on this count you are wrong. More accurately off topic.

TCO is in the ECMAScript specification. See: https://262.ecma-international.org/14.0/#sec-preparefortailc....