Biological Control of Rust and Fireblight

I’ve been trying to formulate a plan for next season for combatting two of my main enemies, CAR and for the first time this year FB. Copper for FB and Sulfur for CAR is what keeps coming up but both come with a negative build up issue and very specific application rates. There are mentions of various biological based products (bacteria strains & yeast strains [honorable mention for apple cider vinegar]) that may be a good alternative but finding people’s experience with these methods that is specific to growing fruit and not marijuana has been tough.

So I pose it here, Has anyone attempted to use biological fungal and bacteria suppression on their trees? How did it go? What sort of rate/schedule did you follow? What product did you use? Was it exclusively biological or some combination of biological with more proven chemical treatments?