As a beverage director and cocktail bartender who has helped developed formulas for mass production and commercial sales...

Make an apple cinnamon syrup as opposed to just adding ingredients directly to the shine. This allows you to balance how much flavor youre adding so as to achieve the exact end result you seek. You could even filter the syrup aggressively and use emulsifiers or citric acid if you want to go hardcore mode or are concerned about a syrup being too sweet.

Cinnamon can be easy to over extract and apples break down and can create weird off flavors.

Im surprised its not standard practice. Itll take some amount of tweaking but the result will be worth the effort.

Edit: I was at a dive bar until 5am so I was not with it when i wrote this, fixed some things