I actually have had some good results with Captan 80, but I’m including it as a routine with early insecticide sprays. It’s very good for scab on peaches, but also helps a lot on rot. Your mileage may vary.
It’s reasonably cheap, so adding it to a spray for stink bug isn’t a big cost. It has virtually no risk of fungal resistance.
It does require an acidifier in the spray solution, otherwise it becomes an insert fungicide very quickly.