The first thing to ask, what parameters to change. Most additives lead to an improved process stability. i.e. I can not specify a numerical value for increasing productivity and/or reducing the roughness.
For given materials and dielectrics (hydrocarbons) a fctor for the improved ignition conditions (reduced ignition delay time)can be specified.
I wonder very much that there are 59 views on this interesting question, but not opinions. I think that there are also different approaches to the analysis. Perhaps all are shocked, because you as concise waiting on a numerical value.
But a discussion of the various types of additives would be very interesting. In 2008 I tried in an article a classification according to the aggregate state of the additive to make. Would be nice if this idea could be continued.