I agree, Gerry, that fast taper would be no good for anything big.
The 2nd video on the website had me guffawing....It took the guy dang near 5 minutes to make his cuts on a 22 or so inch 12-16 foot trunk--with a 200T. I'd have had a big saw up there, and cut past the center of balance with a deep face, and she'd have tipped right over.....or used a pull line.....or simply pushed it over. I rarely use a rope for vertical sections under 20 feet, if the drop zone is big.
Plus, the guy had dismantled the conifer gaffless, as he had left stubs everywhere. What a clusterflock that coulda been.
Maybe Reg Coates (remember his cumbersome Block driver) will like it....
Would this be any better? It looks like a spatula, which is kind of is, but you use it as a lever to tip pieces over. You can also use it to pound wedges if you need. 16" long. Weight? Made by Sandvik.