[Loren]

You're right, it is confusing and will take some incubating.
I'm mainly going on Lynn's instruction on the Collin Neeman
series, Chapter 8 Delivery Path.
In that, and other places, Lynn always says that directing
pressure point #3 directly down the mentally-constructed
straight line from Top to inside-aft quadrant is the same
as tracing the line with pressure point #3.

I'm thinking now along the lines of, when drag loading, the
delivery line of the clubhead is the arc of approach even
with a straight line delivery path of the hands.
10-23-C, Top Arc and Straight line references drag loading,
10-19-C.

In 10-19-C it says "...accelerate the Clubshaft lengthwise....
Maintain this motion until the Release switches ends. This is
possible only if,..., Inertia can hold the Clubhead inside the arc
of the hands or hold to a Line Delivery Path (2-L)."

In fact, 2-L says nothing about a line delivery path. Rather
it's talking about only a Form III lever used in a golf stroke
and that no law of force or motion can be annulled. So that
is no help. Perhaps there is a typo in 10-19-C referencing
2-L?

At any rate, one could hardly go wrong tracing the base line,
or directing #3 in a straight line from Top to inside-aft quadrant
when drag loading. You might notice in start-down waggle that
the clubhead is taking an arc of approach path in either method
of monitoring the delivery line.

When Hitting, you also have an option of using Angle of approach,
10-5-E, a very steep plane and a cross-line bump.

I'll continue to incubate. I'm pretty sure that a line path of the
hands is not particular to drive loading, and that in swinging it
doesn't require an angle of approach, or "cross-line bump".