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• Existing clients are not affected by 1. (BrokerMetadataRequest), but will get the error propagation benefits of 2. (graceful errors).
• Updated clients that add support for 1. will be able to adapt their functionality based on broker functionality and provide meaningful error propagation to applications when proper broker support is lacking.
• Release with 0.9.0.0: Since 0.9.0.0 will incorporate a large number of new protocol request types that the various client implementations are likely to pick up and implement it makes sense to add this new functionality along with it.

Rejected Alternatives