RGeorgy
The Saver Day Pass is not valid in Italy between Milano and Chiasso.
Here’s the link again to the Arcobaleno zone plan (page 4) which should work. Your arcobaleno transfrontaliera ticket to Lugano should include public transportation in the zones 11, 10, 40 and 41 (as mentioned on the ticket). But neither an arcobaleno ticket nor the Saver Day Pass are including any ‘touristic’ cable cars or funiculars to mountain summits (excepted the small Lugano railway station funicular).
Also, you’d need an additional arcobaleno ticket additionally covering zone 12 for the train to Rivera = base of the Alpe Foppa (“M. Tamaro”) cable car, but check their timetable first.
The only added ‘flexibility’ of the saver day pass for your plans would be the also included boats on Lake Lugano (+ zone 12), but I guess it’s way too expensive just for that.