Ceiling with plastering or better fleece wallpaper?

Google "V013_016_Merkblatt Putz. LO4" there is a good overview of which services are behind the Q-classification for each type of plaster. I don't know how the warranty looks with small cracks, whether that is acceptable or not. A statement like: I will plaster it for you, but it will crack, I find strange.

Our walls are Q4 plastered and on the ceiling (Beton-Filigrandecke) there is fleece. I claim that no difference can be seen there.