The deliverable script was easily installed to the client's browser. The client visits the case search page as usual, but now clicks the tool to appropriately auto-fill the search criteria and submit the form.
The search results page is where the magic happens. Clicking the tool on this page begins collecting the results from the entire result set, automatically proceeding to the next page until all the data is collected and the resulting dataset is downloaded to the user's desktop as a standard CSV file.
Now, the client's existing mail merge process can continue as before, except that they have saved an hour or more in the collection process!