From my limited experience with harvesting grains, I would say that oats have got to be one of the easiest grains to mow with a scythe, but one of the hardest to mow neatly. It practically jumps out of the way of the scythe blade, but the grain heads fall to the right, or every which way, unless you use a grain cradle. "Where can I get a grain cradle?", you ask. If I could get them, believe me, I would carry them. Unfortunately, I don't know of anybody that still manufactures a grain-cradle. It's on my list of products to develop for 1SR, but until then you will have to make your own.
Or.... you could try this simple technique. In the video below, these people are implementing a brilliant idea that I have not seen, or heard of before. An assistant to the scyther, holds a light pole against the standing grain, for the scyther's next stroke, which keeps it from falling over, and apparently has the effect of guiding the stalks to move over to the left, just like it would with a grain cradle! I can't wait to try this myself! If any of you get to it before I do, let me know how it works out.
Here I am mowing mature goldenrods, grass, and young bushes, to gain more pleasant access to a wild apple tree. I am using a brand new, 50cm Fux Light Bush Blade, and a 160cm adjustable Swiss snath, and I am periodically honing the blade with a Black-blue Bregenzer whetstone. Highly versatile, this bush blade can be used for full-out field mowing strokes, dexterous trimming strokes, and the kurt bush blade chop. It cuts through woody stems a up to a half inch in diameter. When mowing with a bush blade, I make sure the stubble is left as short as possible.
Of interest to Natural Farmers, and the "to prune or not to prune" debate, is that this apple tree is a wild apple tree grown from a naturally dropped seed, and one of many in the area. It has never been pruned. It just grew that way completely in the wild. It produces a great tasting crop of apples every other year. It's only pest is the coddling moth. We are afraid to mess it up with our good intentions, so it is left the way it is, and never prune it.