Street Demon 625 experience so far

Ignore it.
Are you sure its a lean bog?
What elevation are you at? Most factory setup are for 72*F sea level. If your at high elevation you are rich and need a tune kit. I always tune the secondary door spring in 2nd gear WOT pulls. I'm a TQ guy but the Demon is similar. I run a Demon 750DP and they are good carbs IMO.
Yes I am sure. The wideband pegs super lean at the bog.
Geographic coordinates of Stockholm, Sweden
Latitude: 59°19′57″ N
Longitude: 18°03′53″ E
Elevation above sea level: 28 m = 91 ft