or if I could just allow my page to load arbitrarily deep threads instead of having a limit.
Arbitrarily deep threads become unreadable-- you literally get lines that are one letter long.
A potential solution would be to set a minimum width for comments, and if the nesting would make a comment too narrow, that comment is allowed to extend to the right. But (importantly) it doesn't make other comments in the same thread wider, so you only have to scroll horizontally to continue deep threads.
I feel like I've seen this somewhere, but I can't think where. (Possibly HN? They have arbitrarily deep threads, I don't recall how they're handled.)
It would be a strong partial solution to use the whole width of the screen-- don't let the lines of text for each comment be any longer, but if the comments are deeply nested, get rid of the gray space on the sides and suppress the sidebar on the right.
Getting rid of the grey bars on the left and right (outside of all of the content) would get more horizontal space on wide monitors...
Well, according to this, the optimal line width is about 75 characters. It's behind a paywall for me though. I also found various blogs about typography and web design which agreed with this.
However, according to this, text that extends to the full width or two thirds of the width is read faster than text that is one third of the width. I can't see more details since this is also behind a paywall.
... But the current style holds neither character count nor percentage of width constant over variations in font size.
It would be much more convenient to follow discussions with many comments if "continue this thread" turned that bright green when there were not-previously-loaded comments at the link.