I am towards the end of completing the original story of my character, and then I wanted to transition to playing everything else in order.
Unfortunately, in order to not lose out on some stuff along the way I need to play certain missions ahead of schedule in order to unlock certain things.
I've already played the first two missions of Heart of Thorns to unlock mastery experience points, so all my time fighting would not go to waste before I even read that story arc. Unfortunately, it did spoil some things.
So now I'm faced with two similar situations.
I must complete Out of the Shadows from Season 3 content to unlock unbound magic harvesting, so I don't miss out as I continue to do daily leyline events. But maybe that's not a big deal, unless I will encounter unbound magic elsewhere along the way.
The bigger issue is the raptor mount. I need to do the first mission of Path of Fire to unlock it. Although not an issue of missing out on experience or resources, it is an issue of saving me a ton of travel time along the way. So I'd prefer to do it if I can do the first mission on path of fire without major spoilers.