Hello H & M,
If you are anything like me you are tempted to put all sorts of extra items in the front bottle locker.
Every item adds to the nose weight, so the obvious solution is to be very selective about what you put in the locker.
Do you have two gas bottles? Consider taking just one, many people find that one bottle is more than enough for a weekend stop, and with electric hookups, one bottle can last over a week.
For longer stays or if you know that you will have a high gas usage, it is likely that you would be able to obtain a refill near your destination. The use of lightweight gas bottles is increasing so this might help.
If you still need to reduce the nose weight, as Lutz points out moving mass from the front towards the rear of the caravan may help. Also consider what you put in the bedding lockers, keep lighter things near the front of the van and move heavier items to the rear.
Don't forget that the nose weight is caused by the see-saw effect with the main wheels as the pivot so provided an object is moved as far behind the axle as it was in front then it will be twice as effective as simply removing it.
Clearly you appreciate that carrying a gas bottle in car is not sensible, but moving it to the rear of the caravan is an option provide it is properly secured, held upright, and of course moved out when you get on site.