I'd get another opinion about the possibilities of repairing your soft spot with epoxy injection. The dealer has a conflict of interest. -(Why fix an old boat, when you could buy a NEW boat? Why spend $40, when you could spent $10,000?)
I fixed a two foot long delamination on my old Hobie! I've had to do three seperate injection fixes over the years. The little spots look a bit odd, but my beer barge is still sailing.