Their website isn't very informative but from what I understood it sits between ECU and sensors (temperature, TPS, oxygen) and tricks ECU into thinking that the conditions are different and it should use different part of the map. The simpler products like Sol2, Booster Plug just use air temperature sensor to enrich mixture, and that only works when system is in open loop mode, when you roll on and oxygen/lambda sensor is lagging behind in adjusting mixture. Back to OP according to dealer I talked to part of the loading new map involves TPS calibration, which if it is off you will be chasing your tail. Also the fueling is a bit rough at the bottom, and in my experience on other bikes it could be because of valves tight. I would also replace or at least gut those exhaust cans if not for performance for weight saving. So IMHO the best way to tackle it is 1) adjust valves, 2) replace cans, 3) update to Arrow map and then decide if you need more. The friend of mine just replaced a cat with midpipe on his 890 and it really opened up the bike, both in power and sound. I had an air box clamp pop off on my Superdual and it made bike feel lovelier so it might be choked on intake too. The OEM cans on US bikes have spark arrestors and there is enough carbon deposit so I don't think bike is super lean. Usually the emission- compliant bikes running rich you need some fuel to get catalytic converter, and bike doesn't pop as it would do if it were lean.