After reading that lot JAO must be a bit confused
Basically Alfa never got the timing gear right on the TS engine. It's still a load of old rubbish today. Sure the tensioner has been uprated to the metal version but as suggested it does take it out on the belt. You can't win.
Some will disagree but to be sensible I would suggest the following:
1) First 36,000 miles: cambelt, tensioner, idler.
2) Second 36,000 miles (72,000): the whole lot: cambelt, tensioner, idler, balance belt, balance belt tensioner, auxiliary belt, aux belt tensioner and idler, waterpump, variator.
Obviously the first one is ok but the second one will make the eyes water and your bank manager have a fit. An inordinately expensive routine for a poxy little 1970cc engine that has as much poke as a ferret down a rabbit hole.
Still, there are remnants of character for all of it, so I guess it's worth it