Position a rack in the center of the oven and heat the oven to 400°F.
In a food processor, pulse the flour, butter, and 3/4 tsp. salt until the butter is the size of small peas.
Add the vinegar and 3 to 4 Tbs. cold water, pulsing until the dough just comes together.
Shape the dough into a 1-inch-thick disk; wrap in plastic and chill for 30 minutes. Roll the dough on a well-floured surface into an 11-inch round that’s 1/4-inch thick. Put the dough on a baking sheet, cover with plastic, and chill until ready to use, at least 30 minutes.
In a colander, toss the zucchini with 2 tsp. salt and drain for 30 minutes. Gently squeeze the slices with your hands to release excess water and transfer to a medium bowl.
Toss the zucchini with 1 Tbs. of the olive oil and pepper, to taste.
In a small bowl, mix the goat cheese with the thyme and lemon zest, adding salt & pepper to taste.
Spread the cheese over the dough, leaving a 1/2-inch border. Arrange the squash rounds in tightly overlapping concentric circles all the way to the edge of the dough. (The rounds will shrink as they cook.) Drizzle with the remaining 1 Tbs. olive oil and bake until the zucchini is golden-brown, 40 to 50 minutes.