I keep getting Nth metal but the augment\artifact upgrade screen is tell me I don't have any reagents.
Nth Metal is used to upgrade Artifacts. Exobytes from salvaged gear are used to upgrade your Origin Augments. Episode specific Exobytes are used to upgrade that episode's Adaptive Augments.
Aw, it's a bummer that they've disabled that. The random Nth-metal bits that drop can be real inventory clutter, problematic to deal with during multiplayer instances. Being able to put them on Augments was a quick way to deal with that when there were no Artifacts that could take them.
I absolutely agree that the changes to Nth metal have become an instantaneous nuisance to my inventory. If there are going to be 500 different quantifiable states of Nth Metal, there should be a method to consolidate them for later use. At least with exobytes, you have the ability to upgrade them, but with Nth Metal, they drop at an alarming rate and there are so many varieties that the inventory is just subsumed by them, and unless you've got a mad assortment of breakthrough catalysts, this Nth Metal change is now like having tribbles in my quadrotriticale or a poison ivy rash in all the wrong places. I really notice it on missions when I suddenly fill up on nth metal and then there's a floating item that won't fit into my inventory and I have to pause and do inventory maintenance on a time crunch. It used to be easy to simply flush all the nth metal into augments, but now, if that's not going to be possible, some nice method of fusing them or stacking them or something so they're not a constant, monstrous pain in the flux capacitor would be a welcome game improvement.