
You are getting this all backwards.
While I agree that DMARC interacts badly with mailing lists in general, writing mailing list software in ways that make this worse is not going to help anybody.
DMARC as it exists today has a p=none feature which serves no other known purpose than allowing postmasters to detect which, if any, problems will occur for their particular domain, should they publish a stricter policy.
This detection mission is completely frustrated if mailing lists that are configured to *not* cause problems if DMARC is set to an active policy continue cause false alarms in the p=none test mode.
I firmly believe that the wording about not taking different action for "p=none" is directed only at recipients that would otherwise reject or penalize mail based on the DMARC policy, not at mail forwarders deciding if the e-mail should be handled in a DMARC-compatible way, e.g. by enabling workarounds.