There are a few downsides to this allowance. First of all there are more than a few aftermarket mounts out there that move the motor from its factory location.

With my particular motor I could easily move my motor down an inch or more using factory motor mounts with the stock rubber removed and the window weld polyurethane squeezed into its place. If we allow complete replacement of factory motor mounts it would be even easier to disguise the relocation or even rotation of the motor. Would I personally do that, no. But would other people do that, absolutely. Some people don't mind being that guy, if it helps them win.

Even though this type of cheating is a certainty, I am still 100% behind this allowance. A lot of cars out there really need a better system for supporting their engines than what comes from the factory and at least a few of them are down right dangerous if not checked often. I would personally like to fill my mounts with poly and call it a day. You have my support.