Advanced site handling configuration
For advanced settings the manual editing of sites "config.yaml" file is required, but you have then the full freedom for setting up the fallbacks for connections to Apache Solr server. So is it possible to define different Apache Solr server connection properties, from credentials to hosts, ports and paths for each possible language(content dimension) scenario in your TYPO3 instance.
Finally, after integration for this novelty of TYPO3 it is no longer necessary to "Initialize Solr Connections". Just flushing the caches is enough to apply new Apache Solr connection properties.