Not build threads option?

[mueen at nawaz.org]

Is there a way in the notmuch emacs client not to build the threads for
each query? It can be a bit time consuming. Sometimes (often, actually),
I just want to read all mails from someone, and am not interested in the
whole threads. 

If the above can be implemented, it would then be nice to have a
keybinding that would build the thread, but only for the message being
viewed. 

I don't know if I'm explaining this well, but does this sound
reasonable?