The standard rock guards can be modified to fit a Minuet. The panorama windows are the same size/shape as full-width Argosy and modern Airstream trailers with panos, but the flat center window is narrower.
Here's a thread describing the process.
Several forums members (myself included) have tried removable softer protectors. It wouldn't stop a brick, but should deflect/spread the force of normal stuff kicked up by tires enough to protect the glass.
You can see mine here.
They're Sunbrella fabric over high-density foam, and attached to the Argosy with "Common Sense" fasteners that are riveted to the skin. Some people have made their own, I wanted them quicker than I could likely make them, and had a company in Canada make them that had already made a set for Smokeless Joe's lovely modernized Argosy, so they had a pattern.
I like the fact that the soft covers don't obstruct my view through the trailer in the rear-view mirror, that view through the trailer is nice when towing. The center window is flat safety glass, so it would be possible to have another made without too much financial discomfort.