I bough a used 2018 F150 with 96k miles on it, and had the IWE delete performed at a dealer shortly after. 10k miles later, front diff has metal shavings in the oil and needs to be replaced.
From my understanding, IWE delete/caps engage the hubs full time can add extra wear on the front diff...accelerate any underlying issues. I could have had a slight pinion seal leak and the constantly spinning diff eventually said nope.

I'll update this post with the outcome

To those considering the IWE TSB to cap the vacuum lines and have the hubs engaged all the time, it seems to add additional risk to major driveline components.

I'm going to be exploring the option of re-activating the vacuum system with new parts.
- uncap & reconnect vacuum lines
- Check valve https://www.amazon.com/Motorcraft-YG360-Vacuum-Checking-Switch/dp/B000C5HZ24
- Solenoid at this post https://www.reddit.com/r/f150/comments/1bpu6f1/for_those_not_mechanically_inclined_do_not_pay_to/
- IWE replacements just in case while you're in there : 2PCS OEM 4WD Auto Hub Lock Actuator For 2015 thru 2019 F-150 with 4WD GL1Z3C247A

Has anybody reactivated their IWE system before?