wouldn't be done for steel because the traditional processes are cheaper and far superior. The main issue is that there is not enough surface area in the available lugs, so lugs would have to be fabricated. Fabricating lugs is exactly the same as fabricating the whole frame, thus requiring all the equipment.

Actually, this question comes up every couple of months. My impression is that it is often asked by people that are never going to build a frame, but it if you are, I suggest bamboo. You get the framebuilding experience without the capital expense.