Hi @Robert , looks like you have two questions in one thread here…!
Enabling Delivery Count means that the consuming app can see how many times a message has been attempted to be delivered. Exactly to your point, it might want to try a different strategy. This is a somewhat newer feature, and it involved changing the wireline protocol to include this count with the message header. I forget exactly what the caveats were around using this feature (maybe can’t be used on tiny 100-connection tier brokers?), but just email Solace Support for clarification.
Note that we’ve also had the “max redelivery” setting on queues for a long time, where the broker tracks the number of redelivery attempts (from 1…255). If enabled, these counts are available in the queues’ message details.
Regarding RDP / REST API feature parity with SMF: there are a number of fields that are not exposed or do not map through, both ingress (REST POST) and egress (RDP). If there is a specific field/metadata you need mapped through for your use-case needs, the best thing to do is raise an enhancement request with Solace Support.