I'd have to go with 'subtle' variation rather than mutation. Some of the definitions I found:
Biology - a difference or deviation in structure or character from others of the same species or group.
Curiously, variation within a musical context seems to work for me in my understanding of GCA, as in:
e.A form that is an altered version of a given theme, diverging from it by melodic ornamentation and by changes in harmony, rhythm, or key.
I don't see Ballyneal as morphing or mutating into something else, positively, neutral or negatively. It is still a basicly sand hills or chop hills golf course, treeless, enormously and widely varied sand hill structures, and attempting to present the same general playing conditions of firm, fast, intersting lies in FWs and contours on the greens, utilizing natural occuring factors of wind in the strategy, and appealing to a similar aesthetic and psychological feeling of place.
The family tree is certainly interesting to consider, in a Dye patriarch sort of way. Yet, I don't see anything I associate with a Dye-like style in any of Coore and Crenshaw's work at SHGC, nor TDs at Ballyneal. Now if you could somehow tie old Pete into being influenced by Perry Maxwell, we might have something.
That TD would seek to 'outdo' a compatriot... shocking!