I've been grinding smithing, and it takes a looong while to get over 250.
as of now, the "fine", "masterwork" and "legendary" attributes DON'T DO ANYTHING!!!
in crafting screen it shows that you can gain up to +4 bonus to between 1-5 stats, but when you exit the smithy screen and look at your inventory, the boosts don't stick.
This makes crafting essentially useless, not counting the niche part where you by chance get a tier 5 part early on and can make some good steel.
..or that you really want to make that customized great axe to fit your viking warrior.
Devs HAVE sped up the rate you unlock new parts, though, so that helps a bit.
If a dev is looking at this, you'd need to make crafting more useful, not by speeding up levelling, but by making stat buffs and penalties more common.