Max results for RSS feed

Hi,

I want to find a way to make my Feedburner feed have ALL of my posts as part of the XML feed.
I’ve set the ‘Syndication feeds show the most recent’ setting to 100 in Settings>Reading, which doesn’t seem to work on its own.
Pretty much every single thing on the internet I can find answers this question in terms of using Blogger, where it seems adding ‘?max-results=100’ (or whatever number) seems to do the trick, eg.

from

http://www.YOURBLOG.com/feeds/posts/default

to

http://www.YOURBLOG.com/feeds/posts/default?max-results=10

However, the WP feedburner feed is :
http://bridgesandballoons.com/?feed=rss

So I figured changing it to this might work:
http://bridgesandballoons.com/?feed=rss&max-results=100

…But it doesn’t.
Anyone know how to get a site’s entire blogroll/blog history as an XML feed? (This is what I’m ultimately trying to figure out how to do).

Thanks,
S