Assuming 80mg febuxostat doesn’t result in alarming blood test results or more subjective unbearable side effects I see no reason to change your husband’s dose at this stage. It’s too soon to declare victory over gout even though any reoccurring symptoms ought to be less violent and/or shorter in duration.
Prolonged NSAID use is dangerous however, especially when a PPI such as omeprazole is required.
If it’s at all possible at this stage to dial down the NSAID dose and maybe take it only on the days when inflammation shows up, that’s what I would recommend. If your husband is ever told to abstain from NSAIDs because he took too much in the past (possibly damaging his stomach or what have you), he’ll be in trouble if he gets hit with serious inflammation again.