Can advance AC ferry tickets be used for the next ferry if we’re late?

In 3 weeks, we arrive in Rome just after noon, then take a train to Salerno and then a ferry to Amalfi. If the planes and trains are (mostly) on time, then catching the 2nd to last ferry to Amalfi should be no problem, but would it be safer to purchase an advance ticket for the last ferry of the day? And if we do get there early, can we use that ticket for the 2nd to last ferry? Conversely, if we buy a ticket for the 2nd to last ferry and then arrive late can that be used for the last one or do we have to buy another round of tickets? Or not bother with advance tickets and just see what happens when we get there? We’re just trying to make it to Amalfi to an Airbnb by sunset. any thoughts would be super helpful, thanks!