In the current architecture of the EIP repository, once an EIP reaches a “final” status there is no way to modify it, not even if a security consideration is found.
My suggestion: add a mechanism that is available in the IETF’s RFC repository: an “Updated-by” or “Replaced-by” tag.
This way, a reader of an EIP can clearly see there is further discussion after the current ERC was finalized.
Updated-by should be marked even if the updating EIP is in “draft” (its an “FYI” notice)
Replaced-by should only be marked once the referencing EIP is finalized, and thus the current one becomes completely obsolete.
(both tags are added to existing EIPs once a new document with “Updates” or “Replaces” header tags, respectively, is added to the repository)