$schema introduces specification-level circular dependency

[mathematikoi]

The value of this keyword MUST be a URI [RFC3986] (containing a scheme) and this URI MUST be normalized. The current schema MUST be valid against the meta-schema identified by this URI.

case: a schema where $id equals $schema

the fact that a schema MUST be valid according to its meta-schema, goes on forever! especially if a "validation session" considers a schema and its meta-schema with no further context.

should this be a legitimate concern for implementations looking to be FULLY compliant with the spec?