It depends on how you are supporting the mast, but it is something to think about. The mast "works" a lot when you are trailering, so if you have the mast track facing down and it is on padding, the padding can wear through, and the next thing that wears through is the mast track.

A friend arrived at a regatta with his comptip really messed up and no way to put a sail up. He said he had learned his lesson and would never again trailer with the mast track down. I have also seen aluminum masts with the mast track worn down and distorted from rubbing while trailering.

Some of us trailer boats for hundreds or even thousands of miles, and the mast track is the side of the mast most vulnerable to damage.

Like I said, it is just something else to think about when supporting your mast on the trailer.