if a vehicle stands for a long time in one place, there is a danger that the tyres develop a ”flat spot” where they touch the ground, resulting in an unbalanced, and possibly permanently damaged tyre, so yes, if your caravan stand for months without moving, its a good idea to jack it up.
BUT do not use the corner steadies for this- you will bend the chassis.
get an hydraulic jack and two axle stands, jack the axle up with the caravan on level ground and the front wheel held steady with a chock.
then lower the caravan onto the axle stands at the lowest level possible so that the tyre is just touching the floor.
Do not enter the caravan like this, it may slide off the stands.
the other option, if the caravan is near you when not being used, is just to move it a half-wheel turn forwards every so often, and then back again after a while