Can you link to a particular comment that does the awkward truncation thing? Our truncation process is supposed to address that using a method similar to what you describe. But if you give me a working example I can look into it.
re: "Magical Algorithm" vs "Oldest": what you're problem running into here is a hard-coded edgecase. Very Old Posts were published before LessWrong had a threading system (or indeed, before LessWrong even existed – originally published on OvercomingBias.com). In those cases, some old comments actually only make sense if read in chronological order, and we override the usual settings.
They're more like inconveniences, but still.
1. I've set my account setting to display "magical algorithm" comments, but when I read posts I still see them in the order of "oldest". I guess that's because of a discrepancy between those drop-down options: in 1 it's "top scored", in another it's "magical".
2. The truncation of comments works, but sometimes I find it actually making them longer.
Example: the site displays someone's comment: blah blah blah therefore your argument is i... (Read more) (Click to expand thread. Ctrl F to expand all).
I click Read more. Now it is: blah blah blah therefore your argument is invalid.
So I guess your algorithm of how to display comments looks something like this (pardon my below expression, I'm not a programmer at all):
This leads to the problem as described above. When a comment is 157 char long, for example, this truncate method actually increases the length displayed AND leaves readers like me with a weird feeling after clicking.
Here I propose a solution within my ability of thinking:
So... have those 2 minor things above been mentioned before? If not, I'd like to report. If yes, then are you going to look into them and when can they be changed? :)