Caravanners (and indeed all drivers) should be wary about starting out with towing. It's a massive change to the dynamics of a vehicle, and there are other important factors such as weight limits.
Hopefully they will do the essential checks for weights when they start out, and and get all the details sorted. From that they will have the knowledge of what spare load margin they may have, and gaining some experience, and if they maintain consistent loading etcetera, that may not need to to measure everything quite as pedantically.
But if (as many caravanners find out) they are close to any of their legal limits, you cannot afford to take such a casual approach, becasue it might be all to easy to exceed one or more of those limits.
Not only would you be committing an offence of over loading, it will affect your insurance cover.
Where margins are close there is no place for casual practices.