mellyndc
Alright, on such short notice, the Saver Day Pass isn’t actually a “Saver” option anymore. That >34 CHF price difference just for one or two included short tramway rides in Zurich Downtown (which are not really necessary as indicated in my 1st answer above) would clearly be overpriced here.
In this case, separate, tickets for ZRH Airport - Zurich HB and Zurich HB - Wilderswil could be an option. However avoid the City Ticket surcharge for the second ticket, as your 1st ZRH Airport - Zurich HB ticket would include any ZRH Downtown local transportation for 1 hour after the start of validity of that 3 zone ticket, and that 1h period (as mentioned on the ticket) would begin with the scheduled departure time of the train leaving the Airport underground station (which you bought the ticket for when using the SBB Mobile app!).
So after arriving at ZRH Main Station and having stowed your luggage in the lockers, that 1st ticket would still allow for approx. 30 minutes of free use of all tramways and buses in ZRH Downtown. One scenario then could be to immediately take a tramway to Paradeplatz (near Münsterbrücke) and then to somehow walk back all the way to the Main Station, using as many historic old town lanes as possible (e.g. don’t miss the views from “Lindenhof”)
Just keep in mind that the city ticket surcharge for Zurich City (2nd ticket) would be CHF 8.30, while a single tramway ride (“ZVV short distance”, validity = 30 minutes) would be just CHF 2.80.