I noticed the company lodged a relatively recent patent...

I noticed the company lodged a relatively recent patent application (became public this year, I found it using Patentscope). Its for a diagnostic method, and seems to represent an improvement on the existing one. Its hard to tell how novel it is without referring to the current patents. I expect one can procure these, but I havent done so. I dont suppose anyone has?
Certainly, measuring cell-mediated immunity (ie Quantiferon) has many potential applications (actually, they are listed in the aforementioned document) and they are not totally pie-in-the-sky. Theres a reasonable evidence base in the research literature already for the role of cell-mediated immunity in certain conditions and measuring humoral immunity (ie the first arm of the adaptive immune response) is long established as a tool in diagnostic medicine.
One would assume that CST are exploring other possibilities for their technology, but its impossible to know how close on the horizon these might be commercially.