Ajay, remember you can use the (single level wild card) lora/+/packet_sent in you topic to see all down link messages. http://www.hivemq.com/blog/mqtt-essentials-part-5-mqtt-topics-best-practices
@Jason is the “Request an ACK for downstream packets from the end-device?” a LoRaWAN or mDot feature? e.g if my customer is using a Microchip RN2483 can I use this feature?