ok, so my answer would be that if we accept the hypothesis that all digital currencies require cryptography (which I don't), then by definition all cryptocurrencies will require cryptography to function.
Yes, some day in the future a new type of money may not need cryptography, but (miss context much) your fellow drk supporter was talking directly about cryptocurrencies not being dependent on cryptography which as you just wrote, "So asking if any feature within a cryptographic digital currency requires cryptography is nonsensical because the currency itself requires cryptography already."
Thank you for making my point.