D Murphy writes:

Do I follow that action correctly: the cutting tool is tracing out an
internal hex path by spinning axially and wobbling at the same time?

Actually you are broaching with a hex shaped broach in the case we are
taliking about.

OK, then, does this 1 to 1.5 degrees of tilt and wobble result in a
slightly conical hole being broached, or is perhaps the tool tapered so
that the leading edge is wider than the body, or what?