SG.SetDefaultLanguage only way to load CLDR

[JohnLindahlTech]

Given the following repo and specific row in my loopback-server I'm trying to get Strong-Globalize to work.
https://github.com/JohnPhoto/sg-test/blob/master/server/server.js#L6

If I do not call SG.SetDefaultLanguage('sv'); row I am not able to get swedish to work.
I interpret the call to set sv and then es as the fallback language, which is not what I exactly want to. But I am not able to find any documentation on how I am supposed to do anything differently.

My long haul plan is to use en as fallback language but adding support for request-based support for sv and es with negotiator, as briefly described here.

I am aware that this issue is more of a question rather than an issue, but maybe it can be seen as a request for some improvements in the documentation regarding usage and purpose of SG.SetDefaultLanguage().