Summary: it was a bad spark plug. Get NGK brand. Bosch sucks (for this truck).
Alright so beyond the diagnostics I listed above, I re-ran the compression test with all plugs off and got between 200 and 210 psi on all cylinders. Also checked exhaust back-pressure to check for the clogged cat of doom that these truck suffer from but it held nice and steady at 0.5 psi. Checked MAF signal and it was within spec, changed out the injector just in case, cleaned the fuel rail, checked signal at the injector while running, and traced out all the pins and cables between the A/F sensor and the ECM. Btw, the service manuals listed here are freaking awesome for troubleshooting: Nissan Titan Factory Service Manuals
After all of this I figured it must be something in the ECM so I took it to the dealer for them to check it out. ECM tested fine but the mechanic was intrigued, so he tested spark and fuel too and it looked good to him. He noticed I had Bosch plugs and on a whim he grabbed an NGK OEM plug he had laying around. Put it in and it was music. No hesitation or anything. He said Nissans are notoriously sensitive to variations in spark plug resistance, and that other manufacturers don't have as tight a spec on that as NGK. Come to think of it, when I checked spark it looked a little purple/orange, not the nice bright blue it should've been. I'm gonna order a full set and change them all out. I hope this helps someone!