[grnmnstr]

Front and mid plates, I feel, prevent engine/trans from moving up/down and side to side, but NOT front to back, as the span is so great between mounting points. So therefore a front to back "limiter" would be needed, which would be the trans mount. And I prefer a poly trans mount, than a solid because there is still some chassis flex that needs to be absorbed, or it will find the weakest point and crack it (usually a trans bell housing).
I think people put these engine limiters because they see other people doing it and figure, "if they are doing it, it must be doing something". Also realize that when you see an engine limiter on a car, they might not be running a trans mount. Yes, some people don't run a trans mount.
Not trying to argue, just trying to understand. If it makes you sleep better at night...............