It will be nearly impossible to keep up with the regulations, you have the various government agencies, then you have the various states and last but not least you ave the individual aduanero and all interpret the can import, can NOT be imported differently.
Each aduana and aduanero is an entity on its own when going south, it is a bit easier going North, US Customs are a bit more consistent.
The importation in to the USA depends on the Lobby's of the cattle growers, tomato growers, avocado growers, lemon growers, the Department of Agriculture, you start to get the complexity of the research.
I would suggest that those that have items confiscated report them with the point where they crossed, Nuevo Laredo, Nogales, Etc, and what items where taken and the time of the crossing if it was early in the morning, just before lunch time or close to dinner.
With all this information we can establish what the aduaneros needed for breakfast, lunch or their dinner, then we will avoid traversing the border bfore their breakfast, lunch or dinner but go after, unless they are having a big party and we are not invited then we are out of luck.
navegator