We have an oiled parquet floor and it is easy to use as very little water gets onto the floor, which usually evaporates after 3-4 minutes. We don't have any water stains. I've only had the robot for 3 weeks.
I used to clean the oiled parquet with the Kärcher floor cleaner, which wasn't a problem either, although it left a lot more water on the floor.

We don't use the S8 MaxV Ultra on parquet flooring but on stone slabs. What I can say is that the amount of water used for mopping is low, but it is absolutely sufficient for picking up dust. The amount can also be adjusted in the app. We use the medium setting. The film of water on the stone slabs disappears completely in about 3-5 minutes. Based on my experience so far, I would use the robot on oiled parquet flooring without reservation - if we had such a floor.