I've noticed that some of the TMA frequencies in Switzerland does not match with the correct ATC-unit. For example, around Zurich, SD mentions "Zurich Information", but this is only the FIS-frequency and they can't give clearances by themselves. For TMA crossings "Zurich Terminal" is the correct ATC-unit to contact in TMA-airspace around Zurich for VFR-traffic in class C. For crossings within the non-TMA and non-CTR airspaces (class C and D), "Zurich Delta" is the correct ATC-unit. They give for example clearances to cross corridors and in general class C airspace above FL100/FL130.

In Germany, the non-CTR airspaces in class D and C doesn't have published frequencies for VFR-charts at all, but they are mentioned within the IFR-arrival/departure charts as Radar frequency. For example around Suttgart, this would be "Langen Radar" on 125,050 or 119,200 and around Cologne/Bonn, this would be also "Langen Radar", but now on 135,350. The problem here is the German ATC-company "DFS", which want to force VFR-pilots to contact FIS first prior to cross airspace class C or D.

I've checked the frequencies around Zurich between SkyDemon and the official ICAO-map of Switzerland, and it seems to be 100% in sync. In that case, the official plates are suggesting an inappropriate frequency. Perhaps Skyguide wants you also to call FIS frist upon TMA crossing, however, this doesn't make any scence, since Zurich Terminal does this job for VFR-traffic. As far as I understood from Skyguide, the Terminal controller sits direct next to the departure and arrival controllers. Zurich Information however ist located at another office, which makes a call and further coordination necessary. They also don't have direct access to flightplans, which makes everything more complicated.

Regarding Germany: Would it be possible to display the Radar-frequencies from IFR-plates to the associated class C and D airspaces on the map? I use this IFR-plate "workaround" every time when I want to cross a local class C or D (non-CTR) airspace in Germany. Asking FIS is also an option of course, but on bussy weekends, the FIS-frequencies are overcrowded, limiting the chances of a clearance.