>>1546355The main design improvement in the "modern" era seems to have come in the form of filters, condensation baffles/stingers, and condensate traps like pic related. Or the incorporation of nontraditional materials like aluminium and steel, like in the case of Tsuge or H. Weibe pipes. But they still make up a minority of pipes on the market. Most are still the same old design, because it works.
