They do checks of the tower systems before using it, and have abort contingencies in case something goes wrong during final approach. I'm not sure if they intend (or have fuel budget) for last-second aborts to other towers, or if they just ditch in the ocean (remember there are no humans on the booster).
I'm curious how late in the catch sequence they can still abort.
I'm curious how late in the catch sequence they can still abort.