Ok, so I have a fair amount of time in a Caravan. Let me run this by y'all SE T-Prop drivers. I've never needed to come down in Beta or worse. Idle at a low idle condition and full prop makes for a quick descent. I suppose if one were to go into Beta, you would get a flatter pitch on the blade, but if the blade flattens out, wouldn't the prop over speed at idle and the overspeed governor would kick in? I don't think the prop would do anything at this point. The primary governor would have already adjusted the prop angle to maintain max rpm's. Putting the power lever into Beta lowers the low pitch stop. Now, lets say in the Caravan you get below 140kts and the prop rpm's start falling with the power at idle, you're on the low pitch stop. So if you went into Beta, the pitch would flatten, rpm's would increase again, I think. If the overspeed governor increases the pitch to slow rpm's and goes to an underspeed condition, but then as it sped back up again because you've got it in Beta, your prop would start going ape-• on two different governors. Going into Reverse at altitude just seems nonsensical. You're telling me that you fly the airplane and put it into a position where you have to use Beta or Reverse to get down, I think there's something else that you could be doing.