If you can only get your nose load below your 75kg limit by rear loading in the caravan, then first thing to do is to review and if possible remove any items ahead of the caravans axle, and relocate them behind the axle, or to add some additional ballast behind the axle.
Whilst rear loading is generally not advisable, some times it is necessary. The major concern is the greater tendency towards instability, it doesn't start suddenly, the initial sensations at the onset of instability should be detectable by a competent driver, with enough time to take suitable action.
Speed is always the most significant factor associated with instability, so the first intervention should always be to reduce speed gently, and to proceed at a lower speed until its safe to stop, and to address the problem.