Time expenditure for own services

I would definitely agree that you shouldn't approach this without any knowledge. I wouldn't trust myself to do it without the professionals in the background either. But do you think the insurance will tear open the walls, take fingerprints from the wires, and not pay if there are no fingerprints of the electrician on them?

If an electrical company goes along with it and confirms to you that everything is okay. But I don't believe most are that careless.

You can certainly find an electrician. Some want a complete measurement protocol of the cables and then measure the cabinet themselves. Others conduct a visual inspection of the wiring and only measure the distribution. There are already options.

If an electrical company cooperates and confirms that everything is okay. But I don't believe that most are that careless.

I also see this less as a problem. There are enough electricians who do this. Of course, they don't do it for free. You should just clarify this early on.

This now actually somewhat deviates from the question, since we even have two very experienced electricians, who on one hand handle the planning and supervision, and on the other hand the acceptance. Fundamentally, however, you are of course right that it would be naive to think "I can manage that alone and someone will find themselves to sign it."

Are these electricians also master craftsmen and recognized by the network operator?

Are these electricians also masters and recognized by the network operator?

Yes, both are independent masters, but only one has approval for the area.