I get an option "Hide x comments" next to the "Thread" link where x is the number of comments in the thread that would be collapsed. Do you not see that option? It's possible you don't because I have a paid account here, but as far as I can tell it should be available to everyone.
I don't see that or the ability to edit comments or anything (according to their FAQ, paid communities should have that, I think?). We won't die without it, clear comment trees and expansion seem to be the main things people want, but I'm not sure if it's working as intended or messing up.
Re: Hello! OpenID testing.
Re: Hello! OpenID testing.
Re: Hello! OpenID testing.
Opened up a support request about it here!