Good point, but the definition may still be applicable, even if the state does not rely on the commerce clause... "my client is not a manufacturer"
But in the case of 1224, it's pretty much irrelevant anyway- since the law states "possesses", most of the mention of manufacturer/ing is in exceptions, so it wouldn't help unless you are one.
The only part it could possibly nullify would be 18-12-203, about the required markings for magazines manufactured in the State of Colorado... since a person repairing their own mag is not a "manufacturer"
The whole bill is written poorly, as if it was intended to obfuscate and confuse. (but we all already know that)
I'm also not sure I can afford to pay my Lawyer to explain that in court
and my disclaimer still applies...