Much ado about nothing, imo. I've been climbing 35 years. For the first 14, I almost never ascended a tree without gaffs, unless it was a little fella. Frankly, I never worked with anyone who showed me how to ascend a rope. I was fine descending, even working out on a limb. But,from~1989, when I joined the ISA and started reading, and interacting with good arborists, including the old ISA board (which I didn't post on), I've evolved into a pretty OK arborist, it seems.
Now, at 62, I'm as agile as any of you young'uns...and, sometimes I do a gaffless removal, or part of the job nekkid down there.....Depends on the tree, sometimes it is easy enough...but, even if I choose to rely on my feet for placement rather than the gaffs that are on my feet, they wouldn't get in my way.
As far as the one handing debate, and whether or not someone like Daniel rarely cuts a spar down in short lengths, some of us have done this for our whole careers...and are unlikely to change. Are there safer methods? Surely. But none are as fast or efficient...though I agree they are safer, and should be promoted as such, especially when new climbers are reading. That said, I prefer to take my time more and more as I mature.....and use common sense and caution...try to not get complacent. But you will seldom catch me mismatch cutting a vertical section, until it is over 3-4 feet long. Too slow, and it makes for a bunch of ugly shaped firewood.
Now ya'll can call me reckless if you choose, but I really don't care.
To change the subject a bit, sometimes to save a risky onehanded cut and hold on a limb that I don't want to take the time to lower, I'll sling it, then cut it off past the sling, or pick it up and slide the sling off..or disconnect the biner on the 2nd sling that was set as a crotch from the slung branch. That method requires the g-man to return it to me, or set it aside. Slower.