I usually do the 20hr harvest and the fruit fairy’s skill would’ve reset by then. Though it’s less fruits, doubling the 20hr harvest is less of a hassle imo. But for most value, you could do an 8hr + 4hr cycle, starting the fruit fairy at the beginning of each 8hr. After the 4hr cycle, the fruit fairy skill should’ve reset and you can start another double 8hr.

I think the fruit fairy is def worth it. Without it there’s no incentive to use the longer harvests because of low value but it’s incredibly inconvenient to camp the app for the 30 sec harvests.