I'm not trying to be hard on you guys that don't have a saw constantly connected....
Because many of you still do it that way.
But I've never understood having something that heavy up in a tree that could easily kill someone and not want it attached in case it ever was dropped or came off a hook.
Anything that has a bit of weight has to have a lanyard on it at our company; chainsaw, bolt cutters, drills, etc.
I can't imagine not having an attached lanyard on a chainsaw at all times, it's a useful tool, not only a saftey device.
There will be a few times, where the wind will blow or something change where you need to drop that saw and grab the limb or top with both hands. With a lanyard (even a break away; despite what it says) you can ditch the saw, tend to the limb and not worry about your saw falling.
Also, btw, the above climber would not neccessarily need to be directly above the lower climber. We all have seen how falling objects can ping-pong around and end up far away from the dropping point.