You can always cross them into your other line for the modifier, if you you find something here that has at least some of the traits you wanted. You could grow the generation before grape in your other line, cross with the offspring of your largest here.
Bottom line, only the simplest problems can be solved by growing one cross to stability. 4 parent crosses shake up the linkage and release unsuspected traits. May not do it in seven years, but do it until you get what you wanted!
