I wrote a bit about that a few weeks ago in a post on Greenlanders.

As I mention, the term 'skraeling' seems to have been used for any and all native Americans, as it's used in the Vinland Sagas (specifically the Saga of Erik the Red) for inhabitants of Vinland, which would likely be Algonquin (likely Mi'kmaq to be specific, acording to Mats G. Larsson, Vinland det goda). In any case, these Vinland Skrælings were not the same people as in later use regarding Greenland where it referred to native Greenlanders and hence Inuits. As the other posts mention, archaeologists have identified two cultures there; the Dorset, who were supplanted by the Thule, and the term would probably refer to both of those.

The term is used for Greenlanders already in the Historia Norwegiæ written around 1200, it's likely it refers to Dorset culture people in that context, while later references in the 14th century would have to be to the Thule culture. Apart from that the written sources merely mention them; Bårdsson's 1347 description I translated there is a mere single sentence. So is the 1379 mention of an attack in the Annals of Gottskalk I also mentioned there. (the post you linked isn't really correct in saying there's no references outside the sagas, but there's not much)

Obviously there's more information out there about Greenlanders and First Nations peoples, but the sources mentioned here and in the linked post are pretty much all there is in Scandinavian sources. In other words, very, very little; just a handful of sentences.