The chickpeas can be roasted up to 1 day ahead. Cool completely and store in an air-tight container. Can be served at room temperature or briefly reheated, about 5 minutes at 400º.
Water is the enemy of crunch, so make sure you remove as much moisture as possible after rinsing the chickpeas. Use paper towels to remove any surface moisture, and if you have time, let them air-dry for 30 minutes before tossing with oil and baking.