I hear what you are saying, but the legislation is clear. This act has made repairing vehicles at the roadside an offence.
Whether or not the enforcing agency decides to take action is not really the point. If you repair vehicles at the roadside you are breaking the law.
One implication of this act is how will your insurance company view your illeagal activities should it result in the need for you to claim (or your customer to claim from you) should something go wrong. My guess is that they would use this fact to negate their liabiity and you would be left high and dry.