I don't know that the "thicker oil almost always works" to reduce consumption.
My Forester now has over 205k miles. I have run Rotella T6 5W-40 for most of the time I had it. At most, it consumed a little less than half a quart over 7.5k+ OCIs. At best (and most often), it was essentially unchanged to where my initial fill was.
So, my last OCI, I got a great deal on Pennzoil Ultra Euro 5W-40 @ $2.50/qt on clearance. For whatever reason (TDS gives me no clues why), my engine drank that stuff like fuel... it used a little over 1.5 quarts over the same 7.5k OCI, and I also saw iron wear go from 6ppm to 25ppm. I switched back to T6 on the next fill, and consumption dropped back to essentially nil, and iron dropped back down to 11ppm. I assume some of this 11ppm was whatever was left in the passages and sump during the change, my next OC I will see if iron dropped back to the 6-8ppm range.
To answer OP, additive packages may have some influence if it is getting burned in combustion (effect on ring seal/sticking), but I'd guess it may just as well be evaporating due to high temperatures- next OC try an oil with the lowest NOACK volatility you can find and see how that fares.
/start joke OTOH, if you're interested in maintaining low/zero consumption, Chrysler products probably aren't on your prospective vehicle list
/end joke