Is booking backup ferries to Zamami overkill?

Hi all! I think I need a sense check / potentially overthinking this…

I’m looking into booking ferries from Naha to Zamami (Aka Port) and noticed the usual disclaimer about weather related cancellations (totally understandable). It got me thinking about contingency planning.

Is it common or recommended to book a backup ferry just in case one is cancelled due to weather? I looked up the weather conditions for when we are planning to travel (early May) and it seems like it's on the cusp of the wet season. My plan would obviously be to cancel the unused booking ahead of time if everything looks good, I just don’t want to risk getting stuck on the island if conditions turn.

We’re not under pressure with onward travel (no same day flights), I’m just fairly risk averse and prefer having options locked in rather than scrambling last minute. Is a double hotel booking for Naha and Kerema Islands required?

Would love to hear what others have done or experienced. Is double booking normal? Or am I overthinking it?