Maybe? The following two bits seem contradictory, but you can try the URL modification. :)
"No Threads: You can view comments without threads -- in the exact order they were posted -- by adding ?view=flat to the end of the URL (or &view=flat if the URL already contains a question mark).
Collapsed Threads: With 50+ comments on a page, the comment threads will collapse, so lower-level child comments display as a link rather than the full comment; this automatic behavior cannot be prevented."
I think the intent is more to decrease the amount of data that LJ has to deliver to millions of people, than to decrease what individual users have to download. At any rate, check my comment above -- that URL-suffix technique might work! :)