The Critical time, Processing time and Retries are currently not exposed as Open Telemetry metrics yet. They are still available via the NServiceBus.Metrics package if you’d like to export those to a 3rd party monitoring tool. We’re looking into adding more OpenTelemetry metrics over time but I can’t give you any estimate about the availability at this point.
Have you looked at the information available on the OpenTelemetry traces already? The traces can provide further information about the success/failure and processing time of messages.