Hoi, 20cm is relatively high. I don't think any machine can reach that height. Do you mean about 2cm? Dream e Ultra 50 manages a big hurdle, but 20cm? In terms of cleaning mode, I would always recommend roborock products. And always with an extended warranty. And only from Digitec. This is not surreptitious advertising. But you'll have fewer headaches if something happens.

Yes - it should be OK as without ramp 3cm is fine for this Roborock.

Hello, I have 2 door thresholds of 3 cm in my flat, which Rocky overcomes without any problems. However, your question is about entering/exiting a ramp that overcomes a height difference of 20 cm. I would test this in a shop, because on the one hand the robot has to have enough power to drive up, on the other hand tilting from level to slope is tricky.