> doing so and posting benchamrk numbers showing latency doesn't matter
Ehm what?
> what would matter is if there is anything showing that this makes a difference in the part being machined.
If it would make a difference to the machined parts, either the previous RTAI based implementation or the new Linux-RT-preempt based implementation would be seriously broken.
> That page was big on the 'how to' but utterly lacking in the 'why go to this effort'
We do this, because it simplifies the software a lot and gets rid of all those ugly RTAI kernel modules.