Tyre pressure control system (RDKS) sensors? Recommendation for aluminium or steel rims in winter?

Hi together, I’m looking for wheels and tyres for the winter (Forester SJ, MJ 2018, Platinum). According to the website of a tyre shop, no RDKS sensors are required for the passive tyre pressure control system (RDKS):https://www.felgenshop.de/source/skin/default/img/fsv2/RDKS-Passiv.png On the other hand, with the active RDKS already:https://www.felgenshop.de/source/skin/default/img/fsv2/RDKS-Activ.png Is a passive or active RDKS installed in the Forester SJ (MJ 2018, Platinum)? My Forester shows that In the display no tyre pressures on (unless I have never checked/set this before), so that I go out of a passive RDKS. Then I would not need to order any sensors when ordering winter bikes (wheels and tyres). Correct?EDIT: According to the list of the ADAC, the Forester IV (SJ) has a direct measurement by means of a sensor. So I have to order some extra ones?EDIT-End Does your aluminium or steel rims recommend in winter? What about snow chains? Where can I find information about which snow chains? e Wheel dimensions for my vehicle must be adhered to (boreing, press-in depth etc.)? In the registration certificates Part I and II and in the Subaru Forester catalogue (technical data) I could only find the tyre dimensions (225/55 R18 98V). Thank you for your help!