And another thing. According to 358.6, it says "EMT, factory elbows, and associated fittings shall be listed." I doubt if copper tubing with sharp 90s would be considered listed for that use.
Also, according to 358.2, it says "EMT is generally made of steel (ferrous) with protective coatings or aluminum (nonferrous)." It doesn't say copper can't be used in that article.
