Smarthome - Which system for new construction?

I could also recommend the system "Digitalstrom." With it, we control our blinds very reliably. Not cheap, but no complex KNX, no unstable Wi-Fi, no US or Asian data servers. Meanwhile, it is also easily expandable regarding Alexa, Hue, and co., for those who need it.

Do you only use the built-in logic or with an additional logic server etc.? I have installed the same components, but the automatic shading is not yet activated. What I would like is shading depending on the outside or inside temperature. But for that, I would surely need a logic engine or something similar.

It should work with the actuator. It has the option to control the shading depending on both outside and inside temperature to maximize solar gains. I haven't set it up myself yet. I want to do it based on outside temperature; I consider inside temperature pointless in connection with a slow system like underfloor heating in a new building. With outside temperature, I face the problem that the sun then shines in directly. Shortly after moving in, a collection of fine broken chocolate melted into a lump. It was a Christmas gift, happened just before the turn of the year.

The solar radiation would probably be the decisive factor. Are there solutions for that in KNX? Although it would of course be annoying if the things constantly go up and down with just a few clouds...

A meaningful combination is the season, the presence of the inhabitants, the position of the sun, and the indoor temperature. This way, you can either provide shading or use the sunlight for warming. However, this is hardly possible anymore with the internal logic functions of the actuators. With the shading, much more nice things can also be done.

I still have a few specific questions, but I don't want to ask them here. I don't want to hijack the thread. I will get back to it in my thread.

Do you only use the built-in logic or with an additional logic server etc.? I have installed the same components, but have not yet activated the automatic shading. What I would like to have is shading depending on the outside or indoor temperature. But for that I surely need a logic engine or something similar.

No logic engine or similar is required for that. Both are standard features of the MDT application.
We also had both briefly activated, but it doesn't necessarily make sense for us. The outside temperature does not tell you anything about the solar radiation. At -5°C the sun can still overheat your place...