Cannith Crafting is getting less and less relevant, first with Augments eclipsing it in terms of player-modified items, then with the new lootgen affixes so much more powerful than anything you can craft, and Craftable named items like Cannith Challenge gear no longer scaling up to endgame and being replaced.
To breathe some life back into Cannith Crafting, I'd like to see Diamonds of Crafting +1/2/3/4/5/6 at L4/8/12/16/20/24, respectively. They would let you craft only 1 affix (suffix or prefix but not both) up to +X in value on the item. You could disjunct the item, as usual, to return it to an uncrafted but craftable state. Just as with Runearms, you cant increase the crafting level. You could use Masterful Craftsmanship with it, however, to bring the ML down by 2.
The affixes would raise the minimum level of the item, as they usually do, so this wouldn't make Red augments completely pointless. Also, placing two in a single item would not stack with itself or allow you to craft 2 affixes. Crafting would also still follow the item-type restrictions for non-flexible shards, whereas Augments do not.
They should drop in loot as all augments do, but they should be (non-Store) purchaseable somewhere in game; making them available from Cannith Challenges seems apropos, and covers all the levels 4-20, with L24 (and possibly 28) for Epic Tokens at the Twelve.
I think this would be a great infusion for Cannith crafting. Even named items could benefit from craftable affixes; it would make crafting once again something people put time and effort into, so they could craft shards that only come in Bound form. It would also open a lot of weapons and armor up as potentially useful, since you could combine both Crafted affixes and colored augments.
Some known drawbacks: it'd make DR rubies more or less obsolete, since you could always craft on Metalline or Aligned/Righteousness/Pure Good/Axiomatic/Anarchic...however, I think being able to make more weapons into effective general DR breakers would be a net positive for diversity. It might also devalue normal (non-Epic) Stat diamonds, since you could craft a stat of equal value at any given level, but be able to change/update it easier. And it definitely would devalue Feather Falling/Blindness Immunity/Natural Armor/Resistance/Fortification/Spellpoint etc. topazes, but IMO those are already way too expensive; you'd never spend the money to slot them in anything except final endgame gear.