I made cherry sorbet according to a recipe, only to find that the cherries I'd bought have a strongly bitter taste to them (not unusual for cherries in my experience). Now the sorbet tastes strongly of cherries I'd prefer not to eat :/ what can I do to improve the flavor, either as a last-minute addition during churning (too late for this batch but useful for the future) or a topping? I'm looking to make it sweeter.
Salt counters bitterness. It may seem a little odd to add salt to a sorbet, but I can assure you that it is not unusual to use salt in desserts. Adding salt will also enhance the perceived sweetness of the sorbet.
You won't need much salt. Maybe a small pinch per serving would be enough. Just be sure to note the total amount of salt you add to a batch so that you can adjust up or down in subsequent batches.