Heat oven to 230°C with racks in upper and lower thirds.
Cut zucchini in half lengthwise and score the cut side in a cross-hatch pattern; sprinkle generously with salt. Let sit 15 min.
Meanwhile, place a layer of paper towels on a sheet pan and pour drained chickpeas over top. Use another paper towel to blot dry, then pour chickpeas onto pan. Add 1 tablespoon of the olive oil followed by cumin, coriander, paprika, ½ teaspoon of the salt and several grinds pepper. Toss to coat. Transfer to upper oven rack.
Blot zucchini dry with paper towels. Heat avocado oil in a large oven-safe skillet over medium-high until shimmering. Add zucchini cut side down and cook until browning in spots, ~5 minutes.
Transfer skillet to lower oven rack and roast until zucchini is tender and chickpeas are crispy, 8 to 10 minutes.
Meanwhile, zest lemon into small bowl. Juice half into bowl. Crumble in the feta, then add herbs, remaining 1 tablespoon olive oil and several grinds pepper. Smash with a fork.
To assemble: Top zucchini with feta, followed by chickpeas. Finish with a squeeze of lemon.