Do handicap allowances favor a plus handicap player since it moves their Playing Handicap closer to zero (up), while those above scratch move down towards zero?
A handicap allowance does not favor any particular golfer. When a handicap allowance is applied to a Course Handicap, the resulting Playing Handicap moves closer to zero regardless of whether they are a plus handicap player or a player above zero.
For example, playing at 100% of Course Handicap, the spread of two players, a +5 and 10 Course Handicap, is 15 strokes. In a competition where a handicap allowance of 80% is utilized, the +5 becomes a +4 Playing Handicap (+5 x 0.8) and the 10 becomes an 8 Playing Handicap (10 x 0.8). The spread between those two numbers is 12, which is 80% of the original spread of 15 using 100% of Course Handicap. Relative to a scratch player, both have been adjusted by the same percentage. In this example, a scratch player would receive one less stroke from a plus handicap player and give two fewer strokes to a higher handicap player.
It is not about providing an advantage or gaining/losing strokes, it is about applying a percentage to a Course Handicap to make the competition more equitable based on the expected spread of scores in the specific format of play.