Also, other recipes include luxardo Maraschino liqueur. Maybe .25 oz or less. It adds cherry to the cocktail and doesn’t diminish the booziness if that is a concern.
Tastes do grow, but vermouth doesn’t last very long even refrigerated. As for bourbon. If you’re new to bourbon and are going sweeter, maybe try Angel’s Envy. It’s very smooth. My recipe for you would be 1.5 oz angels envy. 1 oz fresh opened sweet vermouth. 2 dash bitters. A hefty spoonful or two of cherry syrup from the jar. Stir really well. Throw a cherry or two in the final product for garnish. The vermouth type also can make a difference, but you’re right that does get a bit technical here. Which is why I suggest stirring well and throwing in extra cherry to mellow out and blend the overall flavor profile. Cheers! 🥃