The text of the first few words of Romans 7.25 seems pretty unsettled. It occured to me today during a supervision that there are two other readings with better ancient support than the NA27 reading (XARIS DE TW QEW - the earliest proper manuscript support for this is ninth century!); and that the best attested reading was probably EUXARISTW TW QEW (01; 02; 1739; 1881; Maj. syr.; probably also Marcion). If we accept this reading on the basis of the manuscript support, then there is no interjection in 7.25a; but the EGW continues to speak throughout (indeed perhaps until 8.2). Textual criticism and exegesis are hand-in-glove.
Here is a picture of Alexandrinus (02) for this verse: