Unfortunately, this area is not as configurable as it could be… but if you have time to make some changes to improve the situation, I would be happy to incorporate them into a future release of VuFind.
Here is how it currently works:
1.) web/services/Search/Home.php calls initAdvancedFacets() on the SearchObject to obtain facet information based on the [Advanced] section of web/conf/facets.ini. (You can find the initAdvancedFacets method in web/sys/SearchObject/Solr.php).
2.) Advanced facet information is then assigned to the facetList template variable.
3.) The facetList variable is displayed by web/interface/themes/default/Search/home.tpl. This is currently designed to work only for three or four columns, and it includes a special case to make call number two columns wide. This would definitely be improved by better generalization!
I can’t think why editing facets.ini and clearing your cache would not have caused a change to the homepage facets… but you should be able to do some debugging in this chain of code to figure out where things are coming from.
For long-term improvement, it would make sense to add an initHomepageFacets() method to the SearchObject that allows separate configuration of the homepage facets vs. the advanced facets. It would also be helpful to make the home template smarter about displaying an arbitrary number of facets. As I said, if you want to try to make any of these improvements, I’m happy to answer questions along the way. If you don’t have time to do it yourself, feel free to open a ticket in JIRA and vote on it (http://vufind.org/jira) as a reminder that we should make this improvement in the future.