I am not particularly well versed on this specific topic but since your question has not been answered over the past few days, let me try add my considerations:
I know the term 'non-inferiority' as describing a type of trial and don't recall seeing it in the context of indirect comparison. (There is some literature on indirect comparison in a setting of non-inferiority trials but that is something else.)
Therefore I wonder: Would it be possible for you to address your research question working with the established methods and terminology of indirect comparison?
If not, would you please explain why not, and what your research question is and how that question relates to possibly influencing clinical practice and the health of cancer patients?