Hmm ok, I know it's possible to change alternate in flight, and our company manuals do state that the use of alternate fuel is up to the discretion of the PIC (meaning we can hang around holding till we're down to final reserve if we see fit) but I've heard that if you do decide to do something like that hoping to use the other runway as alternate, there are some criteria that have to be satisfied . Such as the runways have to be a certain length, and they cannot be intersecting reae other etc. It's not a company thing, I've heard it's a regulatory thing. 🤔