I wonder if you could move to pure-Go with x/sys/unix to retrieve SO_ORIGINAL_DST instead of leveraging Cgo? It would make cross-compilation for different architectures a lot easier. What kind of sensor results are you seeing with the default setup?
As for results: I’m seeing about one 'hit' per second on a standard VPS. It's a constant stream of bots looking for exploitable systems and probes from scanners like Shodan and Censys. It’s actually surprising how quickly a new IP gets picked up by these crawlers.