When I switch quests in Diablo 3 from one quest to another, I noted that I only have waypoints up until that point. Does that list include all waypoints up to there, or only those I've previously discovered? Unfortunately I didn't take note of which I had and hadn't discovered before jumping between quests.
Yes changing quests gives you all relevant waypoints up until that point. You usually run into them anyway so it's hard to skip them, even intentionally.