My own feeling is that you might have better luck going with an external service like 3D Hubs or Fast Radius if you really need rare metal parts printed for you and you have a design. (Hell, Shapeways does some very nice aluminum-printed bits with good structural integrity as long as the part you want isn't too large.)

The situation for desktop metal printing is a long way – a very long way – from being something that it's a good idea to tinker with. There are some new technologies which look like they might pay off in a few years, but for the moment, you're far better off sticking to plastics and resins than you are trying to get desktop metal printing to do the job for you.

There is a serious difference between being able to print "metal infused plastics" and "metals," and when you're talking about functional parts – never the twain shall meet.