Hello Pchew
Welcome to the SBB Community.
I wondered what is the actual relief of having a confirmation of the confirmation? 😃
But, we do know: travelling in Switzerland by trains, buses, boats, and tramways is very simple. So simple, that people from abroad cannot believe it without having experienced it themselves.
So, YES.
The Swiss Travel Pass allows travel at will on the entire Swiss transit network and this for free according to the passes’ validity map.
https://www.sbb.ch/en/tickets-offers/travelcards/area-validity-map.html
Our trains have free seating; you get on board a train and find yourself a free seat:
https://community.sbb.ch/blog/23887-demystifying-seat-reservations-on-swiss-trains-a-comprehensive-guide
Kind regards,
Roland