I learned that trick from a 65 year old union painter. He was driven
absolutely nuts by a punchlist and an overzealous architect. The
architect set new standards in nitpicking and would attempt to get
20'
walls painted due to a couple of pencil point nicks.

I've been there. I don't think there's anything worse than a painter's
punchlist.... nothing like following the other trades and fixing what
they made a mess of.

Maybe part of the reason I disagreed with 3 coats is because I wasn't a
union painter.
As a contractor, or a sub-, you have to look for ways to do the same
thing quicker [especially on new construction]. I would touch up the
spot itself -- usually that covered, so I went straight to feathering
with a dry roller.

Sometimes it would take more than that, especially on dark colors and
especially on colors made with an ultra deep base.