It's a glitchy fix for Sega Rally at best. TBH it might be mostly luck. With that game, anyway - Daytona and STTC definitely do benefit. I have an out-of-the-way button on the wheel of each cab bound to test mode. Easiest to do things that way, exiting the test menu on whichever cab first, then the second about half a second later. If the link goes real bad, you can always reset it that way without needing to restart the game itself.
But that's for two linked cabs. How the link timing might help with three, or even four cabs, and which cab to start when, i really don't know.