REV has not yet provided any solutions. I understand that they are testing multiple possible solutions, but they do not have anything that has yet shown enough merit for external testing by users.
An external IMU will avoid using the internal Control Hub IMU, but the biggest question is whether or not external IMUs will be affected by ESD similar to the internal IMU. None of the external IMUs that I am aware of have specific ESD protection circuitry - it’s important to understand that there’s two levels of “protection”, the first level is “ESD will not physically harm the device” which the IMU on the Control Hub has, and the second level is “ESD will not cause the device to behave incorrectly” which very few devices actually have. Most external IMUs that I am aware of have neither specifically in their circuitry, though in their design they have features that help them be more resistant.
With that said, I have never heard reports of the Adafruit IMU featuring the BNO055 (like this one) having ESD problems. It also has software support already built in to the FTC SDK.
You can only purchase one if someone is willing to sell it to you. I wouldn’t hold my breath.
-Danny