The wall in the shower niche needs to be made thicker and then the shower would only be 75-80x90 cm and no longer 90x90 cm, which we do not want.
I also don't think the option with the tiles in the corner is bad, but it has to be installed right away when the wall tiles are put up, right?
Which high-quality options can you specifically recommend that one can possibly install themselves?? It should be high-quality and last a long time.