I'm curious if they were having issues with the eccentrics on the third axle. I can't tell from the photos posted so far if they're plastic or blackened metal. Plastic would probably be an issue. You're reaching the limits on clean, easy molding at those clearances, I think. Any mold line, at all, will cause issues there. Could also explain the arms on the eccentrics being one piece.
Might be a small suggestion, there - add the cost for the metal eccentrics.