[ArtOfShred]

There's a few old quests with optional pointer quest steps that can be skipped. Black Marsh is probably the worst of them with a bunch of exclusive pointer quests to the point where it's not possible to do them all iirc. Bangkorai has a good chunk as well, and there's a few in Auridon I can think of.

Unfortunately its not possible to do them if you miss them when they are available. Most are really out of way - there's a quest in Auridon you can start way up north that sends you all the way back to Vulkhel's watch but you can't do it after you finish the zone story in Vulkhel's watch.

EDIT: Also, in the specific case you mention I think the way that line in Stormhaven works is when you complete one of the zone story quests - both the main followup quest and a "breadcrumb quest" that's clear on the other side or the zone get unlocked. So you can do the breadcrumb quest if you find it but if you finish the main step then you can't go back and get the breadcrumb.