Never. Derivation is not a property which can be "lost". Deriving more things through the process of derivation at not point stops the derivation connection. Y

Never. Derivation is not a property which can be "lost". Deriving more things through the process of derivation at not point stops the derivation connection. You should not include code at any point if you do not have the proper license for it. The copyright pollution spreads and any attempt to "clean room it" would be more expensive than re-writing from scratch.