I've recently realized that the V3 downlight will leak via the wire-way through the knuckle. During a recent service call in New England, I found a number of downlights with the lens "blown out" by the force of freezing water. In each case, the fixture was mounted under or rotated below 90 degrees on the branch. Water filled the Greenlee T boxes I've used for years and found it's way into the fixture after pooling in the T box.
In the future, I will only use the V3 FL11 with a side-mounted knuckle as a downlight. I think it will allow me to mount the down light on the side of a branch with the knuckle oriented to drain back to the tree. In addition I have stopped using any mounting j-box that attempts to be "water tight." I decided to treat all "sealed" mounts as potential reservoirs.