Nifty. Trace/space widths? Trace conductivity as a percentage of copper (which is already barely adequate for my purposes)?
My feeling is we need a fully automated photolithography machine for this to become practical. Toss in a stack of fiberglass substrate, and the machine automatically builds one layer at a time, from copper deposition, to drilling, through photoresist spray/exposure/development/etching, to adding another aligned insulating layer and repeating.
Much of the technology that went into TazIntermediate (that 3D printer design I am working with in VR) is intended to field test relevant technology for that machine (which is soon to be published as well now).
For now, if you need custom PCBs, most likely it is for SMD stuff, and for that I think DIY photolithography is still necessary (and not too hard with experience). At one point I was somewhat routinely making my own 6mil trace/space boards by photolithography, soldering those same rivets (or just putting wires through the vias) instead of punching them.