So I am about to start a new group through the beginners box. I have read most of my way through the core rulebook and I thought the answer to this question was yes. However, with the beginner characters while you can spend XP to increase rings the sheets imply that Endurance and Composure do younot change. Is this true or is this just an artifact of the simplified rules for the beginners game?

Certainly in the main game the 'derived' stats do increase as you increase your ring ranks.

Character progression is- deliberately- the most oversimplified bit of the beginner set, since it's only intended for two adventures.