Roy Lewallen wrote:
Source impedance DOES affect the amount of energy moving in and sloshing
around in a transmission line. It DOESN'T affect the ratio of forward to
reflected waves, and therefore DOESN'T affect the SWR.

That's not the question. The question is: Does it affect the SWR meter?
Does the localized energy exchange between two reactances (your own "third
power" term), as alluded to by Chipman, cause erroneous SWR readings from
a directional wattmeter?
--
73, Cecil, W5DXP