If they ever return, they should definitely go into their science more, especially since Terrigen has mystic properties (which can sound contradicting, but not in comics). They should even see what would happen if they can make Terrigen non-toxic, or control it better. It's also worth noting that even though they saw it as something sacred, Black Bolt decided to "gift" it to everyone possible when he thought it wasn't toxic to anyone. People forget that he was planning to do the same thing during War of Kings, but to a larger scale.