This article examines theoretical and methodological issues raised when Legitimation Code Theory (LCT) is used to investigate knowledge-building practices in online and face-to-face teaching environments where English is the medium of instruction (EMI) in non-Anglophone higher education (HE) contexts. The article introduces two dimensions of LCT, Semantics and Autonomy, and demonstrates how "translation devices" were adapted and developed in two studies to analyze lecturers' knowledge-building practices within HE EMI contexts. It then delves into the theoretical and methodological challenges encountered when employing LCT in interdisciplinary studies, alongside other frameworks such as multimodal conversation analysis. Data extracts from the two studies are employed to illustrate the challenges faced and the methodological innovations developed. Methodological implications and potential new directions for the use of LCT in similar problem-situations are discussed, with an emphasis on technological innovation.