That is sort of what I based my half batch spice amounts on. Most people seemed to be throwing 1-2 oz of cinnamon, ginger, clove, etc for a 5 gallon batch. I am only using a one teaspoon, which is about 1/15th an ounce.
I am curious as to why a 2 minute boil would impart the flavours less then a 10 minute boil. I am not much of a chef so maybe its just ignorance on my part but I figured the longer the boil, the less the flavours.