Sanitary pipe installation faulty?

Good morning. We are currently building a prefabricated house with Allkauf Haus and have the Freetime package. On Monday, the sanitary rough installation was carried out and completed yesterday at noon. Unfortunately, all the pipes were laid where a drywall partition for the shower needs to be. Unfortunately, I was not allowed to do this beforehand because the company did not want it that way. Afterwards, I asked for advice in the Allkauf Haus Facebook group, where a member said that the pipes were laid incorrectly. His statement was: I would directly criticize the installation of the wastewater pipe. The 87-degree branches on the floor for the washbasins are completely wrong. You don't do that. The reduction for the shower is also reversed. Did a professional company do this? If so, that is sad! Can anyone confirm these statements? Then I can address this this afternoon! Best regards, Sven

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Wow, can you please stop with comments like that? It really doesn't help anyone. If you have nothing productive to say, please save yourself that...

For DN50, 90° branches are uncritical.

What does pose a problem, however, is the sound insulation:

Are these Skolan db drainage pipes? If so, the sound insulation which was paid for dearly is compromised by this installation: The pipe must be completely decoupled by insulation. That means even where the black nail strips are, the red insulation must be in between.

The connection for the shower is installed the wrong way around; the opening must always be on top at reductions, although this cannot always be observed everywhere...

Where do you properly secure the installation frames? On the gypsum board on the shower side, that won't work, and the wood up there only helps to keep it from tipping over. How much space do you have for your shower drywall + tiles and how much do you need?

At DN50, 90° branches are uncritical.

What, however, poses a problem is sound insulation:

Are these Skolan db drain pipes? If so, the costly sound insulation is negated by this installation: The pipe must be completely decoupled by insulation. That means that the red insulation must also be placed where the black nail strips are.

The connection for the shower is installed the wrong way around; the opening must always be on top at reductions, although this cannot always be adhered to everywhere...

Honestly, I don’t know what kind of pipes these are.. unfortunately, I have no knowledge in this area.

Where do you properly fix the installation frames? It won’t work on the shower-side drywall, and the wood up there only helps to keep it from tipping over right now.

How much space do you have for your shower drywall + tiles and how much do you need?

Where the pipes lie on the floor, a drywall wall with a thickness of 10cm must be installed. Unfortunately, this is currently not possible because the pipes and everything else are lying there and I have no space for it. The pipes lie at the boundary of 1 meter, which is exactly the width of our WEDI element.
If I put the drywall wall further to the left next to the pipes, I only have 80cm left, which is clearly too little!

Does anyone happen to have a picture of what the pipe in the shower should look like the right way around?