The links to the software and command line script are about half way down the product page: https://thunderstickstudio.com/products/tos-grs-4-to-8-way-restrictor-all-in-one-kitA word of caution... I am almost positive that the tos428cl application (required to control the switching via commands etc) is a 64bit app. Normally not a problem but many of us like myself have very light builds based on 32 bit OS like Windows XP. It won't run on any of my XP builds unfortunately.
tos428cl is the command line version you'd wan to use in a batch file:https://thunderjoystick.com/products/GRS-TOS/tos428cl_setup.zip

This is an easy fix if Stefan can compile a 32 bit version. I have been in touch but so far I don't have a definitive answer if this is actually the problem, or if there could be a fix for us with older systems.
And yes I can confirm that you can't switch directly restrictors 2,3,4. Only number 1. Seems like a software bug. I tested thoroughly on my Win 7 desktop.
It's an amazing hardware and Stefan is incredibly talented putting together such quality and top notch products- I'm very impressed. Seems the software needs some tweaking and I'll be in heaven.