Saved Filter URLs do not respect additional parameters

In the new JIRA Issues Macro for confluence, we're trying to allow users to sort and page on the fly, via ajax. We're doing that by changing and appending things in the URL, like a new sort order, or a new pager/start variable. This works well for normal JIRA Issue Filter URLs, like this one:

http://jira.atlassian.com/sr/jira.issueviews:searchrequest-xml/temp/SearchRequest.xml?pid=10240&fixfor=13194&resolution=-1&sorter/field=issuekey&sorter/order=DESC&tempMax=200

However, if you try to get a URL from a saved filter, you get a URL like this:

http://jira.atlassian.com/sr/jira.issueviews:searchrequest-xml/16317/SearchRequest-16317.xml?tempMax=200

New sort orders on this URL are simply ignored, and the results returned in the original order. For example:

http://jira.atlassian.com/sr/jira.issueviews:searchrequest-xml/16317/SearchRequest-16317.xml?sorter/field=issuekey&sorter/order=ASC&tempMax=200

Parameters on the URL should override the default settings of a saved filter.