To test your new feature, modify the MutableSaltedIndexTest to *not* destroy the HBase tables manually by removing the destroyTables() method there.  Instead, add the following code to MutableSaltedIndexTest to change the default of your new config to true for this particular test:

    @BeforeClass 
    public static void doSetup() throws Exception {
        Map<String,String> props = Maps.newHashMapWithExpectedSize(1);
        // Drop the HBase table metadata for this test so that the table splits take effect for each test run
        props.put(QueryServices.DROP_METADATA_ATTRIB, Boolean.toString(true));
        // Must update config before starting server
        startServer(getUrl(), new ReadOnlyProps(props.entrySet().iterator()));
    }

The same change can be made to ImmutableIndexTest as well.