Almost every aspect of Jewelry crafting is under thought
1 Material availability - this is probably the closest to being right with the node availability being from what I can see about 10% of other nodes I seem to come across around 10 of each of the others for every seam of Jewelry material I think 25% - 40% would be more on the money for the base mats when considering how long it will take for the game to become material saturated.
2 Trait availability - beyond Arcane Robust and Healthy these are going to be so tedious to get and past getting each one to research so you can transmute your jewelry to that trait I don't think anyone would bother about the mats and that would be a sad situation if crafting a normal trait ring and transmuting it to the Trait you wanted was an easier grind than getting the trait materials but from what I've seen so far that is the way it looks to be headed.
3 Plating system - This system feels under thought and impossibly grindy if it operated more like the base material refining process where 10x raw mat gives 7-10x refined mat with different modelers like 10x raw gives 3-5x refined it would still be a reduction point but not as harsh and the reduction modifier could be altered depending on material quality green the same as normal mats blue 6-8 purple 5 7 but the current 10 : 1 ration is in my opinion unworkable making common green and blue jewelry crafting an undesirable prospect never mind purple and forget gold upgrading altogether..
4 Master Writs - this is just not at all practical under current conditions there are too many impossible to get mats involved first any trait bar the current live 3 are going to be a major grind therefore worth 20K each at least foresee it being much higher for 6 months plus then to upgrade to purple takes 90 pieces of upgrade materials where would you be going for a writ voucher worth the same as an epic armor piece that costs around 2K to make a 20 x multiplier on the voucher value might not even get you close to the number needed.
Just my view from my time on pts. Hopefully if it goes live in it's current form I will be proved wrong in my views and it will not be as exclusive as I think only time will tell.
Any luck EU char copy will happen this week and I can properly thrash this out.