Every year there are challenges during harvest that send farmers scurrying for aftermarket accessories to deal with those challenges. Lodged corn, soft ears, high-moisture corn, green-stemmed soybeans, green-pod soybeans and other conditions sometimes benefit from aftermarket "add-ons" to help combines deal with unusual harvest situations.
Cornhead reels definitely work when corn is blown over, goose-necked or standing less than good. For those unfamiliar with corn head reels (you lucky devils…), a cornhead reel is a shaft that stretches across the front of a corn head, centered above the front ends of the snapping rolls. Slender arms, call them fingers, extend over each row almost to the snapping rolls. The cross shaft is turned slowly by a geared-down hydraulic motor so that the arms slowly lift and guide downed stalks into the rolls and gathering chains.
Some corn head reels are big and bulky, some are smaller and less obtrusive, but the darn things really help no matter what their size. They aren't foolproof, and won't help when cornfields are literally flattened, but they definitely reduce plugging in fields that are moderately lodged.
If you've had a cornhead reel for several years, be sure to check it over. The spindly nature of the gathering arms makes them prone to cracks. It's a very good idea to look over all aspects of a cornhead reel pre-season (and regularly during the season) to make sure there are no cracks that will lead to an arm or other piece of metal getting fed into the combine. It happens frequently, especially the first day or two after a "used" corn head reel goes to the field and any long-rusted cracks weaken and break under stress.
Green-stem and green-pod soybeans are another common problem that sell a lot of aftermarket accessories to combines. Some guys renovate their entire combine, putting in custom concaves and threshing components to reduce problems with "green beans." In many cases the combine manufacturer offers special concave filler plates, concave covers, smooth rasp bars, extra-corrugated rasp bars or other components that are designed for food-grade crops or hard-to-harvest crops. Before overhauling the entire machine, be sure the combine manufacturer doesn't offer a cheaper, simpler-to-install remedy for harvesting problem.