Usually I flag those answers, under which the comments are not directly discussing the context of the Qn. Either it's only a less relevant part of answer or deviated or a debate. For example, I had flagged this and this answers' comment section to be converted to chat. Or flagging this comment onwards, which don't relate to the Qn. But they were declined.
On other side, similar flags have been accepted in past. This creates confusion on when to flag & when not to.
What is the right policy for converting comments to chat?
All are welcomed to give their feedback on what should be the right approach.
Why this Qn
Due to nature of this site being philosophical & religious, there are less facts and more opinions; i.e. 1 scripture saying something, other saying opposite. A same scripture being interpreted differently from different Guru-s or users. So, comments would be more often about "correcting" each other rather than "clarifying". Therefore this specific policy for Hinduism.SE, being subjective cannot be derived from main SO which is black & white.
Another related post: Guidelines for when to use "Chat" instead of "Comment"