Piper S., don't overthink the process, making pemmican is VERY easy.
To dry the meat, cut into very thin strips, of very lean meat. I cut out all the fat I can manage from the meat to try to get only lean in the dried meat. This is important, otherwise you lose some advantages of real pemmican.
Then take those strips and stick in a basic dehydrator, ideally with a fan, I just added a computer case fan to my basic dehydrating thing, which makes it dry at around 120 degrees, give or take. Ideally keep it below that, otherwise the meat actually cooks, which I discovered on my first rounds of drying meat. You do not want cooked meat, you want it dried.
Drying takes my unit about 36 to 48 hours, and the test to see if it's done is also very simple, if the thin slice cracks, not bends, when you bend it, it's done. It's very easy to feel the difference, and if you leave the meat on for 6 hours more after you think it's done, it will definitely be done.
Rendering fat is also very easy, but you must use a thermometer, to keep the fat under about 240 degrees, more than that and it doesn't taste as good and may lose nutrient values. That's what I read, and that's what I found on my first batch, which overheated a bit, over 250, still fine, but you can taste the difference.
If you want to open the black box, or however you put it, then making your own real food using real grass fed beef ingredients is the way to go.
This stuff is good, really good. Cost for the finished product, remembering that you get about 1/3 weight of fat starting when rendering, but that fat you get for free from the butcher, is about 6 a pound, give or take. Meat comes to about 1/3 or less dried, so the cost per pound is the cost per half pound of dried meat, ie, about 1.5 pounds fresh, give or take.
Do not salt or otherwise treat the meat, that totally defeats the purpose.
There is NO WAY anyone can sell real pemmican legally, it's impossible, the meat is raw. So anything called pemmican is almost certain to be oversalted or some other thing they do to deal with the rawness of the meat. So don't bother looking for it, just learn to make it, I like the process, I usually pick up 5 or 6 pounds of fat, you want the thick chunks, not the gristly pieces, they are easier to cube into 1/2 inch or so cubes for rendering. Also don't worry about rendering the fat to get every gram out, it's not worth it, you gain almost nothing and may end up overheating it, just take it off when the temp starts approaching 240 and you can't readily lower it by lowering the burner temp.
I read most of the online stuff about making real pemmican, it's really not hard, and any how to that makes you think it is isn't accurate.
I store the rendered fat in big jars in the fridge, and thaw it out when I get the meat readied. When it's still liquid, it's really really good. Not slightly good, super good. I suspect non grass fed beef fat rendered is not going to be really good at all, it's quite different from what I gather, different color, and I'm sure different flavor. But when it's good, you want to dip bread into it and just eat it that way, at least that's what I do. But really hard to clean up, you need super hot water and good grease cutting soap.
I'll document it with pics etc and maybe a blog posting when I make my next batch, but this stuff really does last a long time.
To really kick production into gear, get a big pot, thick aluminum bottom for even heating really helps, big size, so you can do 8 to 10 pounds at a time. And you can make your own drying boxes too, it's easy, cardboard, some plastic pipes, a lightbulb etc, a fan if you want, but the regular dehydrators work fine if you use a small fan on them to keep the temps down. Just slower since they don't have a huge capacity.
Grinding up the dried meat is also easy, it just grinds, turns into fluffy stuff, pick out the hard pieces, grind them again, once done, mix the remelted rendered fat in 50/50 by weight and pop into bags or storage, you can use a muffin pan if you want the pemmican in nicely sized chunks, otherwise just put in a zip lock freezer bag let cool then seal. If you did it right it will store at room temp no problem.
I have no interest in eating junk food on the trail, it's just not a thing I think forwards anything positive, and making your own high quality energy food using recipes that were worked out over thousands of years by people who were always on the move strikes me as one of the better ways to actually get with natural systems. You are what you eat, and I don't want to be a sugar powder or junk energy bar, it's not appealing.