If you're sure it is bryopsis, I would fluconazole it. Bryopsis never goes away unless you eradicate it and CUC is hit or mostly miss when it comes to eating it.
Side note, fluconazole shouldn't affect your corals, except for possible side-effects of treatment like parameter swings, which can be mitigated. This is because Fluc works against cell walls, which are present in plants, fungus and algae, but not animals like your corals, nems, fish and inverts which only have a cell membrane.
I'm about to Flux my tank because (earmuffs) FLUX bubble algae!
Side note, fluconazole shouldn't affect your corals, except for possible side-effects of treatment like parameter swings, which can be mitigated. This is because Fluc works against cell walls, which are present in plants, fungus and algae, but not animals like your corals, nems, fish and inverts which only have a cell membrane.
I'm about to Flux my tank because (earmuffs) FLUX bubble algae!