Nifty. You could even use plexiglass for that; maybe even tinted. Hmmm.... We'll need to think about that. Our solar panels are likely going back there somewhere, too.
One thing to watch for with the plastic is any lensing effect: I've seen actual gelcoat & laminate melted by a pair of glasses or a drinking glass set on a cockpit seat! Would be sad if your tiller pilot cooked.

The vinyl siding on my father's house was literally
scorched by the reflection off a neighbor's storm window! Looked like someone hit it with a weed burner.
Edit: You have any plans for a genoa sheet fairlead of some kind? You can see on the edge of our coamings where the jib sheets wore grooves in the gelcoat, & some Ballad owners have wrapped the coaming edge in stainless to protect it. I'm thinking a bullseye with stainless center might do the trick just as well, and it would ensure the ideal lead angle into the winch, too. Prevent overwraps.