Implement ARC as addon to DMARC
ARC solves some problems of DMARC and should be implemented as well
This has become an issue for me as well, to the point customers are now looking at alternate solutions.
ARC is already implemented / supported at major mail providers: http://arc-spec.org/?page_id=79 (e.g. Gmail, Office 365) and Mailman.
Postfix compatible implementations exist via (at least) OpenARC (Trusted Domain Project) and Rspamd
Christian Heutger commented
DMARC will fail similar to SPF on forwarding, which is e.g. supported and widely used in Plesk. You implemented SRS to prevent SPF to fail, ARC is the same for DMARC.