Is moisture a problem with plastic skirting boards?

Thank you very much for your answers. That helps me a lot. Then I will do without the [Leistenschutzband] and simply install the baseboards in a year. That sounds like a good plan.

We are facing the same problem, and there are widely differing opinions on it. We have now ultimately decided to wait with the baseboards, even if it looks ugly. We also commissioned our flooring through our general contractor [GU]. Baseboards are explicitly not included in the offer there. The site manager told us at acceptance that this is because they used to offer it before and there were often problems. Since they installed the baseboards only 6 months after acceptance, and some homeowners then refused to pay the final invoice until it was done, or wanted it done earlier, etc. Since then, the [GU] no longer includes the baseboards. But that gave me something to think about. If a [GU] (who has to provide warranty for it) only does that after 6 months, citing the risk of mold, then as the builder the issue is definitely too hot for me. I can live with 6 months of ugly wall finishing, but not so well with mold.

Then I will forego the protective tape and simply install the baseboards in a year.

Once again: This is not necessary!
The scare tactics about mold are unfounded because the floor construction must already be dry before installing a floor covering. And it simply cannot be drier than dry.
The only reason to install base tiles (and only those) after about one year is to compensate for any possible curling of the screed edges. That means: every cement-based screed can curl during the drying phase. It means: the edges rise slightly, which is not visually noticeable, but in the millimeter range of the visible joint between the wall base and the floor tile with cementitious materials is not always avoidable.
But base tiles, as opposed to PVC or wooden baseboards, are not so easily adjusted in position. And that is why ceramic base tiles are installed only after a corresponding waiting period or, as an alternative, the elastic sealant must later be renewed because it will naturally tear due to the curling of the screed.
But the whole topic MOLD & Co. is, in light of the initial topic discussed here, an exaggerated scare tactic caused by ignorance!

Many thanks to and for the detailed and very helpful answers for me.

I am glad that I don’t have to worry about mold. Because we will be gluing the baseboards, I will still wait a bit to see if there is any potential backflow.

Thank you. It’s very good that this forum exists. I have also benefited as a silent reader in many topics.