I guess this would be sort of similar to the different sorting options for Facebook live video comments. (
Example)
The 3 options for viewing comments on those Facebook videos are:
- "Most Relevant:" some filtering thing that selectively shows only comments from your friends and also "engaging" comments
- "Newest": this shows all the comments in chronological order based on when they were added
- "Realtime Comments": this shows comments in order based on where the user was in the video when they posted that comment
So right now, the chapter-threaded comments on Mangadex are analogous to "Realtime Comments" sort on those Facebook videos. In this analogy, chapter number is like the minute:second of the video.
The feature being requested is something similar to the "Newest" comment sort on those Facebook videos.
One use case for this would be able to easily know when new comments have been added to
any chapter thread for a manga series.