Good luck with that defense! Let us know if they leave you with your belt and shoe laces...
The Federal government defines any vehicle (including trailer and load) 10,001 pounds and above engaged in interstate commerce to be a commercial vehicle. "Engaged in interstate commerce" is loose and up to the local prosecutors office and is impacted by how low the funds are. A LOT of drag race guys have been tagged for that because they engage in a contest with a prize. Not "won", engage in. Prize can be a ribbon -> anything of value. If you haul your buddies 7500# boat -> that counts because you received "value" by the use of the boat and he received value because you hauled it. Haul your own tractor on your own trailer with your own truck to your own land to cut the weeds down. Commercial as you "gain value" in the property by making it neat and clean. Value can be money, services or barter - large or small they tax them all - not dollar will be ignored! Most troopers don't get picky with the mickey mouse bs, but some locations do and have paved the town with gold as a result.
If you are over the pounds, I don't care what you are doing, you WILL be classified as commercial and they WILL find a huge number of violations. No CDL, no med card, no drivers log, no flares, no spare fuses, no inspection, wrong tags, over load, load balance, bad lights, bad reflectors, wrong tie downs, bad brakes, bad tires, wrong load rated wheels, wrong load rated tires, failure to stop at the scales, etc.
Oh, you can prove me wrong by loading up to 30,000#, drive to the freeway scale, blow the troopers a rassy and tell them you are "not commercial" so you don't need to follow the rules! (rassy optional but fun to do)

<-- my expectation of your look 3 hours later when they get done tearing your truck down and hand you the ticket.
jb