Real-time linux can be thought of taking vanilla linux - configuring the kernel in a certain way, booting your kernel with certain boot params and writing your real-time application in a certain way.
While there quite a few hiccups along the way - you will be able to bring down jitter or OS noise to around 1 us. Of course a microkernel based OS like QNX can take you down to around 1 ns - but then the point of using Linux is that you are able to utilize the ecosystem around it.
Look into isolation, real-time patch and high performance computing.
Simulink Real-Time team produces real-time applications from customer models made using modelling tools, ranging domains from aerospace, formula-1 to medical devices and then run them on dedicated target computers connected to real, physical systems. We support algorithms running on multi-core CPUs and FPGAs and we provide instrumentation and visualization capabilities as well.
Will sponsor VISA provided you are authorized to work in the US already.
At this point I consider being permission-less the limiting
factor: if broad "read/modify data" permission is to be used,
than there is not much point for an MV3 version over MV2, just
use the MV2 version if you want to benefit all the features
which can't be implemented without broad "read/modify data"
permission.