What happens to the blind box cover?

I would delete it as the BU says. Leaving it like that would bother me too. It's no big deal.

I am just wondering what kind of cover this actually is. On the outside, the narrow part is the plaster rail, but what is the wide cover on the inside for? If it is a [Raffstorekasten], there is nothing to roll up like with a roller shutter, so it's actually strange to choose such a wide opening. But it is what it is now, and it's not a problem either. I would paint it in wall color because plastering would amount to the same thing but is more cost-intensive.

this is the Bero jalousie box.

that is the Bero jalousie box.

I don't know the Bero boxes. If you have wide masonry (425mm, 490mm), then that might just be an extension of the cover. But it doesn't matter. Just paint it in facade color, then both covers will disappear.

The shutter definitely belongs to the box. We will paint it, although I can only do it on the ground floor without scaffolding.

You can paint from the inside, can't you?