Czuch:  I should have said, "between players of equal rating".  In other words, if match length is the only determinant, then longer matches produce larger adjustments, since the skill factor is greater in a longer match.

Your observation about the effect of a likely win is what I meant when I said

"Where there is a difference between player ratings, the positive
adjustment from a win is greater for the lower-rated player than for
the higher-rated player.  Conversely, the higher-rated player suffers a
greater negative adjustment if he loses than the lower-rated player
would."