Vinyl flooring on tiles, pretreatment

So loops after all and then level out? I have someone who does that, but not cheap. I also want to add that the house will probably be sold again in 5 years, so the investments should be kept within limits.

What I wanted to ask—how was the workload? Manageable? And what did it look like under the tiles?

This is a sh... job with a dust mask, a lot of dirt, and physical effort. I wisely did not participate, but devoted myself to my work until a construction debris container was full.

I don't know if I would aim for the investment if it is going to be sold anyway!

Haha, that is sometimes the best tactic.
Yes, in the background there is always the thought of the sale and what is really necessary... Thank you

There is also the vinyl flooring that can be installed using the "click technique," or am I mistaken? Then only a thin cork mat goes underneath and that's it... That's how we did it at a friend's place!

Yes, it exists and it will be placed in my basement anteroom. I don't really like it in the hallway and kitchen now. I have had 6 different people here and 5 out of 6 said keeping the tiles, sanding them, and filling 1-2 times should be a good solution for the next few years. I'm not looking for something for 30 years now. Vinyl and carpet will be installed and I am glad that everything will be finished by the moving-in date.