My then-12yo neighbor had a hankering to drive his minibike on the road... which was illegal. He then discovered this loophole, and carried a basket of eggs from his mother's chickens. When stopped, he told the cops this was a "farm vehicle", because he was delivering them to neighbors atop the ridge.

They laughed and let him go. Technically, he was legal.

Realistically, he was learning lies work. (He's now a perpetually homeless drug abuser with an increasing criminal record - before somebody jumps to cheer for his cleverness.)

No, there are different standards, between road vehicles, mobile power trains, fixed, emergency, etc. Emergency and fixed tend to have the most liberal allowances. Public road vehicles the most stringent. Tractors are somewhere in-between.

Of course the government exempts itself from this because they know all that bullshit of "it's just as reliable etc" is trickery. It's common to buy previously government owned deleted vehicles, because the people working in federal government don't want to eat the dogfood the plebs do, and AFAIK if you buy it from them then you're allowed to have it.