The `zfs send` command doesn't currently support SIGINFO. It seems like that would be an extremely useful feature. So this is just a feature request. If I get time, I might implement it and submit a patch.
That would not be easy to do, because almost the entire command happens within the kernel in a single ioctl call. Instead, I suggest piping find to pv (from sysutils/pv) for progress monitoring.
Reassigning to the submitter, since this is a feature request. Please close the issue if you no longer intend to do it.
^Triage: close as OBE, as there does not seem to be anything happening here.