The project is called Aesthetics of Design. I presume part of the goal was to build sleek lugless tapered joints.

But, of course, that could have been done with either Filet brazing or Nova sells an internal lug set.

https://www.cycle-frames.com/bicycle...ZE-FRAME-.html

Or, one could do traditional brazing the joints, then filet out slightly beyond the end of the lug and smooth it down to a nice taper.

FrameBuilders Supply also sells blanks that might be easier to shape as desired.

https://framebuildersupply.com/collections/lugs

I suppose an advantage of brazing lugs is it is easier to visualize material layers when finishing.