one question about the usage of comma+V-ing

[Seafood]

Dear Instructors,

Ron mentioned before in some posts that Comma+V-ing modifies the preceding clause and applies to the subject of that clause.

But in the structures below

Subject A + Verb1 + O + that+clause (Subject B + Verb 2+XXX) , V-ing XXXXX
The leaders from different countries eventually reached an agreement that the limitation on XXX should be removed, V-ing XXXX (eg. boosting the sales of XX)

Subject A + Verb1 + that + clause
Eg. The leaders from different countries all agrees that the limitation on XXX, V-ing (modifier)

I dont understand what does comma+ V-ing modify here. The subject A in the main sentence or the subject B in the clause after "that".
Or it can be used in both ways and the usage totally depends on the context of the sentence.

I am sorry for my english and hope the question is clear enough for you.
Thank you very much.

[RonPurewal]

could be either "A" or "B", although in practice it's more likely to be "B".

but, "could be either" is really all you have to know.

[Seafood]

Thank you very much. I just got 760 in my last exam. My SC improved from 34% to 81%. Your lectures and all the explanations you and other instructors made helped me a lot. Thanks again for your help.

[RonPurewal]

excellent, congratulations!