Once I switch my blog domain over to Branchable, the tagged feeds I have submitted to various blog aggregators (e.g. http://feeding.cloud.geek.nz/feeds/posts/default/-/debian) will continue to work (thanks to redirect rules I have generated) but I'm pretty sure that the new feed will have different unique IDs. Therefore, what's likely to happen on many aggregators is that all of my old posts will show up as new.

The best work-around for Planet spamming that I can think of is to limit the number of posts in those RSS/Atom feeds. Either by specifying a "start date" or by limiting the feed to only 1 or 2 posts.

Is there a way to do that in Ikiwiki? Perhaps there's a hidden query string parameter that can be specified on the feed URL? (e.g. max_items=2 or start_date=20121101)