The more important Points of Divergence for the Hilmir Sjot timeline.
Large-scale Colonization of Vinland
A fleet of Viking ships, carrying about 400 to 700 viking colonists, was blown off course by a storm in the year 985, and happened across the Vinland coast. While OTL this fleet returned to Iceland, TTL the majority of this fleet stays in Vinland due to the colonists having found suitable land. Only one person returned to Iceland: Bjarni Hjolfsson.
These colonists founded the city of Hilmirsjot. Hilmirsjot not only more then doubled the population of Vinland in the early years, but the presence of the other nearby Viking town embolded Leif Ericsson to turn the temporary settlement of Leifsbudir into a legitimate colony. Hilmirsjot would also affect the political situations of Vinland for the majority of its history.
Olaf I of Norway flees the battle of Svolder
Olaf I, the first Christian king of Norway, was engaged by forces from the Kingdoms of Denmark and Sweden near the isle of Svolder. Olaf's forces consisted of 11 ships, while his enemies possessed upwards of 70. Olaf was in the position to easily outrun his opponents, but OTL turned to face his opponents and was killed in the process. TTL, Olaf makes the sensible choice and flees, returning to Norway to acquire more forces.
Olaf I survives, and reigns unil 1033. Norway emerges as a Christian kingdom, and is involved in attempting to Christianize Iceland and Greenland.