Suggestion: Crafting Material identification
You know how equipment is marked with a little X in the lower right corner if we cannot equip it? It's a green X if we can't equip it in our current class or a red X if we can't equip it at all. Well, I think it would be nice if that same indication (or something similar) was added to crafting materials as well, telling us whether we can directly use that material in any of our available recipes.
In non-DoH classes, all materials would be marked with an X, but whether the X is green or red tells us whether it's currently useful to us or not, which could make it easier to decide things like which materials to gather or which to sell.
In DoH classes, the lack of an X on certain materials would tell us those are materials usable now by this class. This helps with the problem I'm currently trying to sort out: determining which items to retrieve from my retainer when I want to work on crafting.
Now it wouldn't tell us which items are used a lot and which are only used in one or two recipes. Familiarity with the class would still be needed for that. And when players reach the upper levels of a crafting class and no longer care about items only used in the first tier or two, it doesn't help with identifying those. But I think it still would offer enough to make such an identification worthwhile.