I think this will help for servers with a large number of jails. The time savings is small for a minimal install - 2 seconds. For larger systems, it will be more.Running the rc scripts on large servers may take somewhat longer, especially when several jails have to be started. But again, starting a jail is I/O-bound. And it should also be noted that – unlike desktop machines – servers are not booted every day in the morning, so then it doesn’t matter that much. Just my opinion, of course.
The nice thing is the change is actually quite small for sh(1) changes - about two paragraphs of RC script edits.
I rewrote the C code for rcorder(8) because I wanted unit tests. The resulting binary is about 5kb larger.
Another nice thing is backwards compatibility. You can run new rc script with old rcorder or old rc script with new rcorder. Everything still works. No speed improvement but you can boot.
I'm curious how much faster to see the login screen for mate or slim.
About netwait ... other rc scripts that don't require it can continue to run.