Can Q2 plaster be wallpapered with fleece wallpaper?

We bought Q2 and thought it would fit. Walls crooked, partly fist-sized holes or bumps, strong wave formation. Also, no wall is properly plumb. So the only disaster. Q2 perfect at friends'. So it depends heavily on the skill of the plasterers and less on what is on paper. But you get used to it and come to terms with it. Gives the house a rustic look. Some even pay extra for that.

As already mentioned, a well-done Q2 plus non-woven wallpaper and painting can be sufficient.

This still does not answer my central question - why is it mandatory to paint? My original question is not about a white paintable fleece, but explicitly about a colored, textured non-woven wallpaper. Can I hang it on a well-done Q2 and NOT paint it? Or is there a technical reason against that?

My in-laws have pasted non-woven wallpaper with a pattern on Q2 and it doesn't look good - pimples everywhere. But as I said: it depends on the substrate.

I painted to conceal the transitions of the non-woven wallpaper strips on the walls and ceiling. In addition, the white wallpapers were more cream-colored and not pure white.

That is a good argument, with the transitions, that you see the erased parts less. Thank you