Saisons are one of the most versatile beers, and lend themselves to a wide variety of additions. If your yeast leans to the pepper & spice, you can go with spice-based additions. If your yeast brings more banana or other estery flavors and aromas, you can easily add fruit.
Many recipes call for a small amount of spices, with coriander, peppercorn, seeds of paradise, anise, ginger and lemongrass being some of the more common additions. An addition of chai would be an unexpected twist. (May I suggest calling it a Chaison?)
A wide variety of fruits will work well a saison. Berries like raspberry and blueberry seem like they would match pretty well. Peach and apple are highly rated, but have more subtle flavors that may be more difficult to bring out in a saison. A watermelon saison would likely be very refreshing for summer quaffing.
I’ve never seen a pear saison, but I can see the subtle sweetness of the pear really balancing well.
As saisons can be sour, I can see tart additions working well. I’ve made a rhubarb saison that worked surprisingly well. Hibiscus would be another one that I can see bringing an excellent tartness and beautiful color to a saison.
While saisons are quite flexible, there are some additions that would be difficult to pull off. The usual suspects like bacon and mint make that list, but also nuts, which are difficult to pull off in a lighter or yeast driven beer.
BJCP Style: 25B