@7suh Thank you for the links, I hadn't really looked beyond the Todd one before.
As far as I can tell, MMRs are identical to the certificate transparency scheme (RFC 9162, formerly RFC 6962), and the FlyClient paper seems to agree:
The idea had been proposed before in the context of certificate transparency logs  to show that any particular version of an append-only log is a superset of any previous version.
So my second paper is not doing the same a MMRs, in fact it outperforms MMRs. Or are you saying I should present MMRs as the progenitor and CT logs as the reinvention? This page states that google started developing CT in 2011, they had running logs and an RFC in 2013. Given the whole complexity of the rfc (MMDs etc), chances are they had the merkle tree construction a lot earlier. So I'd be unconfortable to present one as definitely preceding the other.
But I'm definitely going to cite MMRs, probably via the FlyClient paper.
Reading these also pointed me to vector commitments, which will make it into the related work section of the first paper.