"My father is past the age of trapping". What does age have to do with it? If he can stand, he can trap (standing with assistance on the side of the boat)! Trapping is much easier than hiking. Besides, unless you two weigh almost nothing, it would take a pretty high wind speed to disadvantage you with only one not trapping off the rack/wing. Based on your perception that dear old dad cannot trap, then he probably would not be racing at all at such a high wind speed, so what difference does it make? The ratings are for the boat, not the sailors. Perhaps the word "handicap" in the ratings rule has given you the wrong impression.

Your request would have the same effect as asking for an allowance for not using the trapeeze when the wind is light. If the racks get you and your dad out racing and allow you to compete better, then the ratings adjustment seems appropriate as it is allowing you to hold the boat down better than you could without it, right? Otherwise, you will open a real can of worms trying to get ratings relief for anyone unable (temporarily or permamnently) to best utilize the equipment on their boats. While that may seem unfair to you, that is not the purpose of the ratings rules and the available adjustments. They are designed / intended to make the boats even, not the crews.