Is it a good idea...

Don't think so, as it will only create unnecessary additional load for the server, which in turn means longer page loading times for the other monks... And frankly, I think that manually reloading the page when you actually want to look at it, isn't such a big deal.  Just my 2 cents.

Recently Active Threads has an RSS feed. Just use an RSS reader and the feed and everything will go automatically.

Yes, that's a really good idea.

Sorry can't find this "RAT feed". There is a feed for new nodes and a feed for new threads.

But IMHO no feed for active threads ...

Cheers Rolf

What XML generators are currently available on PerlMonks?;

Oh - I mistook the RSS icon on Recently Active Threads to be a feed generated for it, but it seems that it is just the RSS feed for Newest Nodes. So there seems to be no explicit RSS feed for threads.

If this were a user-selectable option, perhaps. I'm not sure what value is added by having Recent Threads reload automatically, given the effort involved in doing it manually when desired.

If you are looking to detect new nodes quickly, perhaps one of the node tickers listed at What XML generators are currently available on PerlMonks? might serve your purposes.

im2's telnet stream notifies you about new nodes.