umm, no. just no. fungibility means that two units are interchangeable/equivalent. Legality doesn't enter into it. anything that makes unit A perceptibly di

umm, no. just no. fungibility means that two units are interchangeable/equivalent. Legality doesn't enter into it. anything that makes unit A perceptibly different from unit B can cause humans to value unit A more less than B. Some units may be perceived as "better" than average and carry a premium. Others may be perceived as "bad" or "tainted" and trade at a discount. Such differences are generally considered undesirable in a money.