None of it matters if the controls aren’t responding. You’ll know, too, because they make that sad static beepy noise like some sort of Tactile Control Panel ACKnowledgement failure.
I’m betting they sprung for the cheaper Cardassian ones without the redundancies. O’Brien is not going to be happy.
He does feel more comfortable having those Federation tertiary backups in case.
Considering all the weird encounters Star Fleet vessels encounter over the run of a TV series; who can blame him?
Well, in a crunch I wouldn't like to be caught without a secondary backup.