Socket placement

Good, clear that this is not for a single outlet.

I am currently weighing whether to outsource additional outlets externally and not have the main contractor electrician do it.

Plus a few other network/electrical things.

"My" electrician also has no problem if I provide the materials myself. Which is actually a bit cheaper when I check prices.

What is the wall structure? A lot depends on that. Poroton, GK, wooden stud or KS—there are big differences.

Poroton bricks and some drywall

Hmm then it is quite simple and quick. Both just get quite dusty (so only with a vacuum). Should not take longer than 5 minutes for a professional.

Ah, wow... so fast after all.

Okay, clearly that's not for a single outlet.

I am currently weighing whether to assign additional outlets externally and not have the general contractor electrician do it. Plus a few other network/electrical things.
"My" electrician also has no problem if I supply the materials myself. Which is actually a bit cheaper when I check prices.

Does the general contractor just allow this so easily? Is the general contractor electrician directly employed by the general contractor or was the electrician hired by the general contractor based on a tender? Couldn't the general contractor electrician agree the service separately with you, meaning you simply get a quote directly from the electrician without going through the general contractor?
Have you asked who assumes the warranty for the electrical installation?