Some filaments (like steel-infused PLA) recommend and/or require the use of a "hardened steel nozzle". Is this the type of nozzle that comes with the R2? Also, it seems some 3d printers allow the replacement of a nozzle w/o having to replace the entire hot end. Are we able to do this on the R2? If so, is there any reason I wouldn't be able to put a nozzle with a different diameter on there as long as I adjusted that setting in the slicer? I was thinking a .2 mm nozzle might be better for miniatures.