The Roborock can certainly manage about 2 cm, if they drive at the right angle onto an obstacle, then even 2.5 cm. In order for the robots to overcome obstacles very well, you can also put silicone rubbers on the wheels, which are actually intended as protective covers. The main problem is not the actual height, but the fact that the wheels are made of relatively hard rubber and therefore don't lift well on the edges of things.