What quality consideration should prompt storing chopped garden herbs mixed into unsalted butter and frozen in a cylinder?

To extend the herb's usability for up to a year while allowing controlled portioning

Herbs naturally contain volatile oils responsible for their flavor, and these oils typically lose potency after about six months to a year when stored conventionally. While freezing herbs in water cubes is an option, it can dilute the flavor during subsequent cooking steps. A more advanced technique suggested for extending their usefulness involves incorporating them into fats. By chopping fresh herbs and thoroughly mixing them into unsalted butter, forming the mixture into a cylinder wrapped in wax paper, and then freezing it, the volatile oils are better protected within the fat matrix. This method not only successfully extends the herb's practical usability for up to a year but also offers the convenient benefit of allowing cooks to slice off precise portions as needed for various culinary applications.