Telehandlers are machines which are meant to operate in rough environment, although, that doesn't mean that they could be driven without any regard for the terrain. These types of equipments have a much bigger risk of load loss or tipping over when they are traveling on slopes.
If you do need to travel on a slope, ensure that you proceed carefully and slowly while keeping the load low. Prior to getting on the slope, downshift to 4WD and a lower gear. Using the engine brake would really help to control the speed of the telehandlers. Try not to turn on a slope if possible. If you must make the turn, take it as wide as possible and use extreme care.
Under any conditions, avoid driving across extremely steep slopes. Descend and ascend slopes with the telehandler's heavy end pointing up the incline. Even when the forks have no load, the machine's counterweighted rear is quite heavy; therefore, it could be required to drive backwards up slopes. When the telehandler is carrying a load, the front of the unit becomes the heavy end, and you could back the machinery down the slopes.
Operator training is extremely important on a mixed jobsite. Rear pivot machinery would usually operate on the same jobsite of coordinated steering equipment, where everyone is allowed to use all of the machines. In this instance, a person who is used to operating a coordinated steer equipment could jump onto a rear-pivot machinery. A very key difference between how these two units operate depends on which part of the machinery extends outside of the turning radius.