This is probably one of those “Ask ten bakers and get ten opinions” type questions, but here goes...
With grains where you have a choice (oats for example), do you bring out the flavor of that grain more by using the flour or by doing an add-in (assuming equal percentages of the grain in the final dough).
My two cents is that whatever processing the grain receives prior to use has a strong correlation to its flavor contribution. Example: toasting a grain before using it will modify and intensify its flavor. Or, grinding to a meal or a flour will provide more surface area than flaking, which could enhance enzymatic modifications with, presumably, more effect on flavor.
Paul
... and you added another element I hadn’t considered: toasting. I’ve got a recipe I’m toying with, and I guess I’m going to have to make about six versions of it to see which one I like best!