SolrSearch.php $additional_search_types should be settable via the yml method (or rather, these values should be retrieved using $this->config()->additional_search_types rather than $self::additional_search_types.)
I've moved this issue from extensible search to here for now (I will soon PR the code that moves this configuration across), because as much as it would be nice to just make the change, this isn't entirely backwards compatible for projects that have already used this configuration.
I've moved this issue from extensible search to here for now (I will soon PR the code that moves this configuration across), because as much as it would be nice to just make the change, this isn't entirely backwards compatible for projects that have already used this configuration.