Finally got this figured out. Was too focused on the ETC air source and missed the somewhat obvious solution. Had to disable all three of the Trans torque management switches. I'm not sure which one was causing the throttle to close as I disabled all three at once but it now works. On a side note, I finally had a chance to make some passes Friday night. Just foot braking it as I didn't have the trans brake figured out yet truck went a 12.72@108 mph. I think this is pretty decent for a 15-17 Gen 2 F150 with just a few bolt-ons and no weight reduction. After reviewing the logs I think there may be a couple tenths still in as it short shifted 1-2 and timing was low. Couple this with being able to launch at 3,000 rpms and a low 12 may be possible.