In a colander set over a large bowl, toss together zucchini and 2 teaspoons salt. Let drain for 15 minutes, stirring occasionally. Working in small handfuls, wrap zucchini in ultra-fine cheesecloth and squeeze out as much liquid as possible. Place drained zucchini in a medium bowl; repeat with remaining zucchini. Reserve liquid for another use.*

In a large bowl, whisk together eggs, thyme, garlic powder, pepper, and remaining 1¾ teaspoons salt; stir in zucchini, green onion, and pimientos. Gradually sprinkle in flour, stirring until well combined.

In a 12-inch nonstick skillet, pour oil to a depth of ¼ inch; heat over medium heat. Line a rimmed baking sheet with paper towels.

Working in batches, drop egg mixture in 2½-tablespoonful mounds; flatten into 2½-inch patties with about ½-inch thickness. Cook until golden brown, about 2 minutes per side; transfer pancakes to prepared baking sheet. Repeat with remaining egg mixture.

In a medium bowl, stir together jelly, mustard, vinegar, and garlic until well combined. Serve immediately with pancakes. Garnish with thyme, green onion, and pepper, if desired.