Oh wow super interesting. This article from esa explains the actual 3D printing process, a stainless steel wire is heated using a laser and melted onto the print surface. It's funny that this would actually work better in the vacuum of space. With a large robot arm maybe you could 3D print big space truss structures.
They also talk about a circular economy, I guess you could melt old bits and turn them into wire and then recycle them.
Looking at the test print, the next step might be to have a separate tool to mill the 3D printed surface so you have good tolerances. E3Ds ASMBL toolchanger had something like that. But collecting the metal shavings in vacuum and microgravity could be a problem :D