Hello,
I started looking at this RFE (new matching rule) and pushed the design https://www.port389.org/docs/389ds/design/matching-rule-in-chain.html
It is in a preliminary state but I hope covers major part of the RFE. Feedbacks are welcome :)
This RFE relies on another RFE (https://github.com/389ds/389-ds-base/issues/5156) that I will start to look at.
regards thierry