Wow... What a nice implement...!!
I met a cottager once, who told me he had a better technique than a chainsaw to remove tall trees (not necessarily dying ones)... Sounds a lot like your tool.
He explained to me that he uses the 2K lbs winch mounted on the front of his Dixie Chopper zero-turn. Using *very* long cables, he would attach a cable as high on a tree as his extension ladder would allow. Then, he would park his mower 100+ft away, wedged against the trunk of another large tree. Then, he would slowly let the winch do its work, pulling the top half of the tree down, bending it, until the roots would give. Voilà! No stump to grind out!
Apparently works most of the time in his mountainous region. But, I can imagine that depending on the tree type and soil conditions, that approach might never work, as the tree would snap its trunk midway instead of the roots giving out...
Next time you use your implement, it would be great to see a shot of your tool being used when it is not inline with the fall direction of the tree.
Cheers,