Confirm that BlindedExecutionPayloadEnvelope stays an SSV-internal container

[ovidiu-ssv-labs]

Summary

The beacon-APIs specification does not have the BlindedExecutionPayloadEnvelope container. PR ethereum/beacon-APIs#624 removed it. SIP-94 §6 and the node still use this container. We must confirm that this is correct.

Facts

1. The specification has no Gloas.BlindedExecutionPayloadEnvelope schema. Only the pre-Gloas blinded block types stay in the specification.
2. The node publishes the full signed envelope to /eth/v1/beacon/execution_payload_envelopes (beacon/goclient/gloas_envelope.go:75). This agrees with the specification. Issue ePBS §6: treat EXECUTION_PAYLOAD_ENVELOPE_ERROR_ALREADY_KNOWN as success on the envelope publish (§6 analog of #2922) #2923 made this change.
3. The node uses the blinded container as the QBFT value for the §6 duty (protocol/v2/ssv/value_check.go:202-211).

Effect

There is no known effect on the wire today. The container is internal to SSV consensus. But the container name is the same as the name of a removed specification type. This can cause confusion for a reader.

Request

1. Confirm that the blinded container stays an SSV-internal type.
2. If the container stays, add a comment in the code and a note in SIP-94. The comment and the note must say that beacon-APIs removed the type, and that SSV keeps the type for consensus only.
3. If the container does not stay, give the replacement container.

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Found during Glamsterdam QA research (test plan P0.1 / P0.11). Verified against ethereum/beacon-APIs master on 2026-08-26.

[momosh-ssv]

Confirmed: BlindedExecutionPayloadEnvelope stays an SSV-internal container. It is consensus-only and never goes on the wire; §6 publishes the full SignedExecutionPayloadEnvelope. The type doc records this at protocol/v2/types/gloas/execution_payload_envelope.go:21, citing beacon-APIs#624. Closing.