IMO, ingredients in primary and secondary give the most depth of character/flavor though there are instances where that isn't the case. Some ingredients, like strawberries, take a very large amount in primary to not get destroyed by fermentation and hold on better when used in secondary. I like whole blueberries in primary and carry them over with racking until the fruit is mostly white.
Roasted cacao nibs work better in secondary, unless you want to get some of a coffee like bitterness from them in which case you might use them in primary for that and then also in secondary for that chocolate flavor. My limited experience is that cacao will start to fade after a bit and you may need to overshoot that desired flavor if this isn't for close to immediate consumption.
I don't really have much experience with cherries and I've seen a lot of posts about them giving a cough syrup like taste. I believe that actual varieties of cherries used has a large impact on what you get in that regard.