Agree with IHL. While I can't speak for Bell products, I can say I've experimented with the ADI for flight in IMC in an S76. After many years of cloud time, I've determined (for myself anyway) the best thing to do is to leave it alone and accept what it shows you in flight.
It's only my opionion, but if you re-adjust it in flight, you may forget to reset it later on. If it's a real low vis day and you're a bit tired, who knows, it may be the difference between having or not having an embarrassing moment at the end of the flight.
