I have just bought a KTM390 and the buzz on the 390 forums is to fit a booster plug. I understand the Indian equivalent of Euro 5 , BS6 tends to make the bikes run so lean they can stutter at low revs and also run hotter. There is lots of chatter on the type of fuelling closed loop and open loop, which I dont understand. However it sounds like the booster plugs are most effective in the low range , hence stops stalling , whilst at higher revs have less effect which is why Orinoco’s mpg doesnt suffer.
In the early days of F650/800 ownership on here lots of folk were fitting booster plugs to clean up low speed fuelling and that was back in 2008/10 so its proven tech.
Steve