ESP8266/RFM95W node - How long should a send take?

That doesn't feel right. But it does depend on the packet size. Like sending a 50 byte packet on SF12 takes 2.8 seconds on SF12. I guess that implies the node starts to listen for a response after 3.8 and 4.8 seconds, but I might have that timing wrong. The TX_COMPLETE would only be triggered after both the first and second Class A receive windows have ended.