Right, I have also heard that they keep lists of that. By the way, they also check whether a supposed interested party is a broker themselves and might simply want to pass on (or buy) the property.
The agent we will work with for the sale is making a great effort. Regarding, for example, photos, he came to the apartment together with a photographer and took photos for about 1.5 hours. These will be used, among other things, to enable a three-dimensional "walk-through" of the apartment in the listing later.