A helmet workshop in Hedon London works on a smaller scale than a mass production line, and that shapes almost everything about how a helmet gets made. Materials are chosen and checked by hand, shells are shaped and finished in small batches, and problems are caught by people who see every stage, not just a sensor on a line.
Neither format is a universal answer. Weather, speed, journey length and personal comfort all play a part, and many riders end up owning one of each for different trips.
Visors are a wear item, not a lifetime part of the helmet, and most riders find a spare on hand is worth having, especially before a long trip.
Anti fog inserts and coatings help in cold or wet conditions, but they are not a substitute for a visor in good condition. Once scratches build up to the point where they catch the light on every ride, it is time to replace rather than keep cleaning around the problem.
This is slower than fully automated manufacturing, and that is the point. A handcrafted shell trades speed for a level of finish and individual attention that a purely machine made helmet does not offer.
A leather trimmed helmet needs a little more attention than a plain shell, but the upkeep is straightforward. Dust and light dirt can be wiped away with a soft, dry cloth, and any marks are best treated with a product made for leather rather than general household cleaners, which can dry the material out over time.