GU is building without a final factory plan

But from your answers I conclude that it's different on construction sites and absolutely normal.

Unfortunately, "normal" on construction sites means that it deviates exactly the other way around than with you – and to an extent that is called a "problem" not in the mathematical, but in the dramatic sense. Be happy with your luck (even if Stoppok is otherwise often right with his "trouble" – especially in construction).

If your changes are taken into account in the construction, it seems everything has arrived there.

What good is 100% planning if you, for example, also change things afterwards.

We also work with a general contractor and some things were changed, deleted, or added after the final planning and everything was implemented without updated planning.

I think it also depends on the communication between you, how binding your contact person is.

Our site manager has so far implemented every "called out" change without him or me having agreed on anything in writing, for example shortening a wall on the upper floor, moving the door of a room, swapping a door for a sliding door, and some other small things.

Next Friday is handover for us and everything has worked out so far.

All fine and well if it is built correctly. However, at least the plans in the building application should correspond to the agreed ones.

The question is when the OP submitted the last requested changes. If that was AFTER the building application, everything is fine. If it was before, it’s not so great.

I don’t see any pitfalls for the OP as long as they have communicated the requested changes in writing.

However, I can understand that as a builder one would want to have current plans on the construction site. But that would not change the fact that as a builder one should still regularly check like a watchdog.

Meh... Monitor execution according to change requests, insist on appropriate planning documents towards the end, be happy.

insist on appropriate planning documents towards the end,

I personally (however, as a draftsman, I was also trained by Gotthilf Penibel) would not build a house without detailed planning and would not recommend it to anyone – one knows the horror pictures of drywall bumps, after all. But it is indeed permissible to build purely according to the plans to be submitted with the permit application if one trusts one’s workers to virtuously interpret them accordingly. Schinkel or Palladio certainly did not draw or mark exactly for the craftsmen where the waterproofing slurry should be applied, and they are still considered great master builders today. Wanting the general contractor to provide a drawing documentation afterwards for the family album, in my opinion, is somewhat already performance phase 9 and certainly not part of the construction service description without a separate agreement. As always, both gastronomic laws apply ;-)