Given the proposed focus on FEP implementations being discussed at Implemented FEP type?, I’m wondering how new implementation data is going to be updated in FEP documents with a FINAL status.
Personally, I think there are disadvantages to putting implementation lists in the FEP. In some cases, an implementation might be directly related to the content of the FEP and that makes sense to include in the document (e.g., an FEP was derived from an implementation or the FEP is documenting a feature in an implementation). However, simple lists of implementations do not change the primary content of the FEP when the lists change. I think these should be tracked externally to the FEP. This could be an IMPLEMENTATIONS.md (or json) file in the fep’s directory, for example. Another benefit is that the format of that file could be specified to make parsing easier for automated tooling.