Grrrrrrrrrrrrrrrr!
It does not seem possible to have two feeds with different amounts of posts in them, with podPress. There are two settings – a global setting for “how many posts are in a feed”, and a podPress-feed-specific setting for “how many posts are in this feed”. But the podPress one is ignored, as far as I can tell. So this may not be possible after all. Is anyone a podPress expert?