We've had scanners on our preload for a while. If you were trained with scanners as a new preloader, there isn't really much to it once you get the system down. Scan it, load it, come back out for the next one. Once you get familiar with a set of trucks, the mornings go by relatively smoothly and driver bitching is kept to a minimum until management decides to change things up for reasons.
That being said, our preload operation is as much a mess as any other. Most problems stem from inadequate training, which in our building effectively amounts to "Welp, there's the truck, and there's the numbers. Good luck!" That and the fact that they're desperate enough for help that they'll keep any bum with a pulse past 30 days. But nobody really gets taught how to plan for space or work the belt and avoid stacking out/falling behind. You're basically left to figure it out on your own and learn from other preloaders and drivers when they whine about your load. I know for me it took a solid 3-4 weeks to really figure out the job.
For peak this year, they got really creative and brought down a couple girls who only knew how to sort smalls in the mezzanine and put both of them on 3 trucks. 500ish pieces on each truck. Results: Predictable. Stacks, misloads, tears, and salty drivers.
The drastically differing driver attitudes toward preload continues to amuse me though. Some drivers can barely mask their disgust at the miserable treatment and working conditions, others just can not help but pile on and add to preload misery. The latter are the ones I always hope have new hires loading their trucks.
Newer drivers who were preloaders within the last few years typically seem to get it, but the ones who are 10-20+ years removed from preload sometimes have a hard time grasping how different it is now with many of us handling 900-1100+ pieces in 5-6 hours, all while the pay still sucks. We had a 12 year driver who had to bump inside for ~6 months from mid-summer all through peak last year and said he'd never complain again about everything not being in his truck when he shows up in the morning. Said the volumes were never this high and the pace of the job was nothing like it is now and that he'd never be able to keep up. That's a driver who always gets a good load.
tl;dr preload sucks. Go driving.