Group Specific Sorting and Threading

[Les Harris]

Apologies if this is easily found.  I can't seem to find how to do it:

Is it possible to have different sorting and threading functions on a
per group basis?

I have a group using the nnrss backend and the feed comes with posts
newest first and threaded. For this group, I would like posts to be
sorted oldest first and have no threading.

Ideally, I would like a way to do this on a Topic level, so these
settings would apply to all groups within a topic.  I may be getting
ahead of myself with that though.

Any help appreciated.

-- 
Les Harris