David Weaver
I've never studied metalworking tools of any type other than misusing files and body files on my own stuff.

Is there a benefit to TIN of making the non-critical parts of the tool more friction resistant to soak heat away from the cutting tip? I'm sure if it became popular, it proved itself out well.

The first spiral router bit I ever got years ago was HSS with TIN coating. I don't know that it was actually intended for wood (a friend got them) and I bought carbide after that.