Telehandlers are machines that are meant to work in rough terrain, although, that doesn't mean that they can be driven without any consideration for the terrain. These equipments have a much bigger risk of load loss or tipping over when they are traveling on slopes.
If you do have to travel on a slope, make sure that you proceed carefully and slowly while keeping the load low. Before getting on the slope, downshift to 4WD and a lower gear. Utilizing the engine brake would actually help to control the telehandler's speed. Try to avoid turning on a slope if possible. If you need to make the turn, take it as wide as possible and utilize extreme care.
Under any circumstances, do not drive across excessively steep slopes. Ascend and descend slopes with the heavy end of the telehandler pointing up the incline. Even when the forks have no cargo, the counterweighted rear of the machinery is quite heavy; therefore, it could be required to drive in reverse up slopes. Once the telehandler is carrying a cargo, the front of the unit becomes the heavy end, and you could back the machine down the slopes.
Operator training is extremely essential on a mixed jobsite. Rear pivot machinery would usually operate on the same jobsite of coordinated steering machinery, where everybody is allowed to use all of the machinery. In this case, a person who is used to operating a coordinated steer machine could jump onto a rear-pivot equipment. A really key difference between how these two units operate depends on what part of the machine extends outside of the turning radius.