See Chazon Ish I mentioned previously. Here’s a link to it and the discussion on the CR:
http://www.hebrewbooks.org/pdfpager.aspx?req=14336&st=&pgnum=158&hilite=
etc.
As I mentioned regarding the app, and it’s true of the switch as well, these are not from the more subtle cases of zilzul Shabbos. These are obvious ones.