I use it regularly In course when discussing the principles. I learned it from Bruce Smith from On Rope.Just out of curiosity, is the T-Method (T for tension) for calculating mechanical advantage widely known amongst arborists? I've taught it in rescue classes for years, but can't recall a mention of it here.
I do not know of any others using it in regularly. Most likely because as arborists we tend to use “set” systems of known MA and or, the system in the tree is so over engineered with so many variables from rope angle to anchor flex, trying to quantify MA would be pointless.