An AFR of 12.2 may be a bit on the rich side, fuel economy might not be great. In the end choose what you feel makes your bike run the best for your riding style.I'm sure some of you have read a couple of my posting about Takegawa 4v BBK kit grom that walked away from my BrianS 170 BBK grom going up the Hills in San Francisco and this is the Grom above that is owned by JDracer, I say he has one of the fastest grom out right.
Not sure if he had any luck with the 10 hole F/I that we got.
Looking at his settings 12.2 and 12.5 my PCV-WB02 unit sees 12.6-13.6 with the best power pull when the reading shows 13.2-13.4 A/F
Here is a quick video that goes over Air/Fuel Ratios and what characteristics you might see for different AFR values.