Leveling compound on waterproof concrete basement floor: from when is it possible?

@ Mbk84: Thank you for your feedback. Please consider that the room can only be used subordinately later on, because a sealing layer should not be taken into account. WU concrete does not mean that it is vapor diffusion tight!! So if such a structure is in the groundwater, there is always increased humidity (and all associated disadvantages) to be expected in the room adjacent to the floor slab!! Just as a side note. Good luck with and on the construction measures: KlaRa

Thank you, I have now received many very valuable suggestions – especially also critical ones, which sometimes help much more

We are considering whether we will still "treat ourselves" to the screed in the two remaining rooms