Center rail support
Ryan, I would assume that the bulk of the weight of the boat is supported by the center runner and the side runners are 'extra' support, to stabilize it from flopping over of course. I would not recommend using only the side supports to hold it on the trailer while you do this work, as you could end up caving in the hull. I think the center/bottom support design and the way the weight is distributed about the length of the centerboard make this area more physically capable of sustaining the whole weight of the boat. Unless you only remove a portion of the runner where the damaged area is accessible an allow the bulk of the weight to remain support centrally. A call to Hunter would be in order here before using side only.The best and safest way to do this is to hoist it, then support it distributively with proper stands or do the work while its on the hoist.It must have damaged it quite a bit for you to want to repair it. I would think this one area of the boat sustains highest risk of collision and hence the bulk of 'damage' thru the boat's lifetime. So I don't even think about keeping this part of the looking good unless it affects the boats performance somehow. A little rounding off is probably a good thing!Be careful and good luck.Brian