Serious build ADHD.
I decided to go ahead and jump into the truck weatherstrip. A couple things I learned:
Use more adhesive. I did a fairly small bead on my first run probably 1/8", you need more than that.
Smaller sections are better. I did the whole top section of the trunk first and that was way more than I should have done at a time. According to the 3m instructions you're supposed to put adhesive on both surfaces and let dry until tacky before joining them. 4' of adhesive'd weatherstrip leaves a lot of potential to get it everywhere. So next time I'll do maybe 1.5-2' sections at a time.
I inadvertently did something that I think helped. When the weatherstrip came in I put it in the channel without adhesive, just to check out the shape and fit. I left it like that for a couple weeks waiting to get back around to it. I think this kept the weatherstrip from twisting up as I was working on it.
The weatherstrip is an odd shape, be sure of which side you're applying adhesive to. One of the nova books says to put adhesive on the bottom of the channel and after installation come back and put adhesive on the outer wall of the channel. On one 2' section I didn't pay attention and put adhesive on the inner face of the weatherstrip thinking it was the bottom. Thankfully it was a tighter section of the channel so all sides will make contact and it won't burn me.
The upper corners are the only places I'm not thrilled about. I wish I had done just the corners by themselves. I did the corners and a good section of the trunk side all in one go. I think the corners need more attention to make sure you give them plenty of material because the weatherstrip is supposed to make contact with that outer wall and I don't think mine will. Doesn't look terrible, but I could've done better.
I kept seeing recommendations to use a Popsicle stick to spread the adhesive, I just put on rubber gloves and smeared it with my finger. It dries quick so you won't get it everywhere.
Much thanks to @Custom_Jim always helping out around here. I found this post and I helped me feel more confident about the task, especially joining the two ends.