Cecil, W5DXP, quoting others, wrote:
"The reflected power wave doesn`t travel from the load back toward the
source and the extra 4.17 watts in the forward wave doesn`t travel from
the match point back toward the load."

Users of the Bird and Similar wattmeters know that is what they see.
Source and load power is the forward power minus the reflercted power.

Zo of the coax enforces its volt to amp ratio on both the incident and
reflected waves. Reflected power is again reflected at the match point
because the matched source sees no reflection. That`s the point of
producing a match in the load.

Best regards, Richard Harrison, KB5WZI