The Jerking is complete.
Thoughts:
-Overcooked the first batch I believe, at 3.5 hours. It's still edible, but doesn't bend without breaking and some of the edges might charitably be described as crispy. I guess I expected it to be softer somehow.
-The thickness of the cut has a lot do with it I think. I had them go thinner than an 1/8th of an inch and that has a big impact on how much wiggle room you have on cook times. If it's thicker it has to cook longer but it probably stays more pliable. Thinner and the line between not cooked and overcooked is much smaller. My oven might also had something to do with it.
-It absolutely needs to sit in an air tight container for a few hours after cooking. Eating some 10 minutes after cooling out of the oven, it was very dry and brittle and I was kinda like "oh god what have I done." After a few hours in a ziploc, it did get softer and more pliable and definitely tasted like and had the texture of jerky.
-Doing it in the oven, you have to contend with one issue: fat. Even with the leanest cut of meat I could get, after a few hours the fat pockets in the meat liquefied and sat in little pools and crevasses of the meat, giving it a greasy, shiny appearance. Because the fat doesn't actually go anywhere, that means it's still there and in a few weeks will probably go rancid. So this isn't the kind of jerky that will keep for weeks and weeks and weeks in an air tight container. Not sure how you're supposed to deal with that, other than trying to cut all the fat out of the meat before cooking which seems like wasted effort. I guess that's just one inescapable side effect of using an oven vs. a dehydrator. Maybe hanging the meat in the oven as opposed to letting it lay flat would help some of that fat run off the meat during the cooking process.
-Flavor is good. One marinated for about 9 hours, the other about 12 and I don't see much difference between them. Wondering what a 24 hour marinade would be like, but based on this, it seems like it would be a bit much.
A fun experiment and I'm keen to try it again sometime. This was about $16 worth of meat. Compared to what you get out of a ~$8 bag of jerky at the grocery store this is way, way more affordable.