Just installed this translation and realized the lang HTML setting is set to lang="es-LA" by default so I was wondering if it can be changed to just "es".
I know it could be done by editing the template but there are also some other settings like dir that confuse me.
The language code comes from the specific language setting. You may be able to change it to what you want by changing the "Locale" setting for the language, but there for Spanish, there are always specific versions based on location.