If you want a saucier end result, you might consider doubling the sauce. If it were me, I'd only pour half of the sauce over the sheet pan ingredients and cook per the recipe, and then take the other half of the sauce, stir in 2-3 teaspoons cornstarch and bring to a simmer on the stove to thicken and use the extra sauce for serving.
Feel free to sub out the vegetables in the recipe for other favorite choices like asparagus, cauliflower, other types of squash, etc. - you could easily add cherry tomatoes, too.