The base plate was cast too large - it has now been shortened - is that okay?

Sounds good. I would still quickly measure the important connections. It's not rocket science and check with the [Plan]. I only know it that measurements are always taken from the shorter side to the outer edge. Don't want your drain to end up in the middle of the wall or 16cm in front of the wall.

In the rear area there are no pipes, only the grounding electrodes. However, they should be within tolerance. I will measure it again to be sure. Is a "cut-off" base plate actually worth the same price as if it had been done correctly from the start?

You do have the written statement from the structural engineer that everything is fine and no problems are to be expected. As I understand it, the defect has been repaired. Why do you not want to pay the full price now?

You do have the written statement from the structural engineer that everything is fine and no problems are to be expected. As I understand it, the defect has been fixed.
Why do you now not want to pay the full price?

I did not say that I do not want to pay. The question was whether the slab in this condition is worth the full price.
A repainted new car, for example, is also not worth the new price - so please allow me this question.

I never said that I didn’t want to pay. The question was whether the floor panel in that condition is worth the full price. A repainted new car, for example, is also not worth the original price – so please allow me to ask here.

Then ask if you can get the 16 cm detached floor panel.

So if scratches in the paint are properly repaired before the delivery of a new car (if necessary by replacing the affected parts), you will certainly not be granted a discount, but it will simply be kept quiet that there was a defect. After all, it is still a new car without defects.

So I see no reason to withhold anything here.