English grammar often has overlaps, and terminology is difficult to keep track of. Recently, I've been reading about disjuncts and discourse markers, which has led me to think that this might be one of those cases. Consider the two examples I have provided:
As you know, this case has been ongoing for several years.
In other words, the case is a dead end.
I have made these up, but they follow the same format as examples you might see online. In my opinion, both are disjuncts and discourse markers. The only difference I can identify is that discourse markers can be interjections — such as 'well' or 'right' — but disjuncts are typically adverbial, their purpose being to provide a general attitude/opinion regarding the sentence.
That said, are all disjuncts a common type of discourse marker?