When my wife's iPhone 7 decided to use up the battery at an amazing rate I rebooted it, and it bricked itself.
It was in recovery mode and couldn't be taken out. Fortunately I had a backup from 30 minutes earlier. Unfortunately iTunes 12.6.4 could not restore iOS 11.3.1 and I was going to be forced to update iTunes to 12.7.x to get it done.
I stupidly forgot that I could manually install the ipsw file if I downloaded it myself, and instead blew $$ money on REIboot app for Mac since the free version could not kick it out of recovery mode.
I had to re-install iOS 11.3.1 via REIboot, but it was nice that I didn't have to restore 64GB of her data back to the phone at 2:30AM after the IOS restore, as it was all still there afterwards.
Can anyone confirm that you can indeed install iOS 11.3.1 (restore to factory) using iTunes 12.6.4 and option-clicking on "restore" ??