Engine shut off while driving

Oh, okay, that's great. Good idea. I forgot they rent out tools. Hope for the best.

Okay, I know it takes a lot to get to those timing chains, I very surprised you are not seeing some huge failure. Do you have the oil pan off, can you look up and see the crankshaft and connecting Rods?
I wouldn't be looking for an engine just yet, because we don't know what really happened here. Is it also possible to get a look at the Flex Plate at the rear of the engine? I believe there is a cover that can come off to get to the Flex Plate and Torque Converter bolts. I wonder if the Flex Plate broke off the end of the crankshaft. I was just going over our first comments, so you did find some kind of plastic chunks in the oil when you drained it correct. As of right now I'm kind of just throwing ideas out there. If you were able to get the oil pan off you might be able to see if a Connecting Rod broke, but since you can't turn the engine over by hand even with the spark plugs out, you'd think it would be an obvious failure. Will the engine rotate backwards just a little bit? And I remember a crankshaft position code. Do you remember what the actual code number was? The diagram below shows the Starter Motor removed and you can see the teeth of the Flex Plate. If you pull the Starter maybe, we can get a look at the Flex Plate. Can you take some pictures of the timing chain setup when you get a minute? I just want to see how far into this you are and if I notice anything. I know you're limited with time, so whenever is okay. I'm here every day, I was really thinking you would have seen a valve stuck in the top of one of the pistons, but since everything seems ok in cylinder, I'm thinking lower end or the flex plate issue. It's very difficult to help when not being at the truck with you. But snap a few pictures of the timing chains and anything else you think is relevant,
One last thing, you have both valve covers off, check up top there. Any of the rocker arms fall off or anything jammed into one of the camshafts? Even with the timing cover removed it still won't turn or have you not tried that yet? The thought of the oil pump seizing up just came to mind, I believe it's part of the timing cover assembly.
This engine just has so many components.
I just came across this diagram too, the Crankshaft Position sensor has its own trigger plate attached to the Flex Plate, I've never seen a design like that before.

It doesn't note on All Data and our other database is down for the time being. It doesn't look like it is. I can see the small section you mentioned. Even just getting the Starter out looks like a big job. I think the upper oil pan removal calls for something like 9.9 hours, if I'm reading the warranty information correctly, So, I would say that includes pulling the motor, or at least raising it somewhat with an engine hoist to get at the oil pan. But I would go for the Starter first and see if something happened to the Flex plate or that crankshaft trigger wheel. I don't know if work on the engine has been done in the past, but there was a Bulletin on making sure the Torque Converter bolts were installed correctly if it has been apart in the past. That most likely doesn't apply to your situation though.

I can see the oil pump can seize onto the crankshaft in the front. I found a video of the same engine that won't turn over either. I can link to it if you want.

https://www.youtube.com/watch?v=Fr1LUnFh8wA

Locked up engine due to piston wrist pins.