I'll jump in here if I may. The noted setting makes it just a bit richer across the curve. This also corresponds to that chart from the bbpower settings for slight perf mods. I verified this by plug reading. Stock (and good state of tune otherwise), plugs were dry & white. Linked as above and in the midst of a ride, the plugs were a very light tan, dry. Post mod idle is also notably richer and very smooth. Great off idle transition. No surging anywhere.
This tells me the increased richness is slight and should not gob things up over time. Also, I think my bike could be a tad more rich without detriment. My only concern is that when the temps go up, my pinking may come back to some degree unless I can richen it up a bit more. Might have to experiment with some other links, as noted in prev posts. I'll worry over it when the time comes. This change is indeed a big improvement.
Edit - and to Bacon's question. No cat code plug is the richest setting of all. Don't know what to tell you if it's still lean.