Preparation for non-woven wallpaper

We want to use Raufaser fleece from Erfurt. There are just small bubbles on the plaster and a few edges where some craftsmen bumped into. The defects should be repaired by the handover of the house. However, we want to wallpaper the stair area beforehand because it's easier to reach. Once the staircase is installed, it will be difficult. We just don’t know yet if they can fix it before the weekend.