In my case, I think the Swiss Travel Pass is more suitable because we also plan a lot of train travel.
Thanks for your information about the refund. However, I got a message from SBB after I filled out the refund form following your suggestion:
"Thank you for your query.
An exchange, alteration or refund of the order 54041109544 is no longer possible.
Saver Day Passes that you purchase in the SBB Mobile app or on SBB.ch while logged in can be refunded/exchanged free of charge within 30 minutes of the time of purchase. Once those 30 minutes have elapsed, Saver Day Passes cannot be refunded or exchanged as a basic principle.
You can find here detailed information on the conditions of sale. "
Shall I contact SBB again?