Ok, thanks. I will keep an eye on this.
My takeaway is that if we want to maximize our pass benefit, Pontresina - Chur - Disentis - Brig - Zermatt will be best.
If we want to combine Bernina Express route (using regional train) and then continue, we purchase separate ticket from Tirano-Chiasso (or Locarno – which appears to be cheaper than ticket to Chiasso!), and from there continue to Domodossola - Brig - Zermatt.
Just to confirm - technially Chiasso - Locarno - Domodossola route or train doesn’t change. We will be continuing on the same train regardless of ticket switchover point.
