No, you do need noise, but not for hours on end. It lasts maybe 10-15 minutes (I haven't timed it).

In my case, the noise only lasts about 1 to 2 minutes. During this time, it cleans the wipers and pads and probably sucks the vacuumed dirt out of the bag. Then the cleaning phase ends and the appliance remains silent... Maybe the entrance to the dock is a bit cramped and the robot has problems parking and doesn't dock correctly?

The noise that lasts for hours (2 hours) is the hot air used to dry the wipers - but it is not loud.

No. When the dust container is vacuumed into the dust bag after returning to the base station, it makes a brief noise. The mop pads are then dried, but this is quiet and not disturbing.

I think this is normal. While the battery is charging, the Ultra also dries the wipers and this makes a bit of noise.

No