First of all, thanks to
@DuckMe . I have an iPhone 13 with iOS 16.2, which I downgraded to 15.6 RC, and I have successfully updated to 15.7.2 RC.
I bought an iPhone because of its great software and battery backup, but iOS 16 changed that. I waited until 16.1.2 and upgraded from 15.7 to 16.1.2 and 16.2. Battery backup on 16.2 is not good. Even in idle condition at night, it drops to 6% (now my 15.7.2 drops to only 1%), and while using the 16.2 battery, it is not as good. So I finally decided to downgrade from 16.2 to 15.7.2.
I successfully downgraded from 16.2 to 15.6RC for the second time (the first time stuck at the Apple logo) using an ipsw file.
I have been stuck at 15.6RC for 4 days searching for how to update from 15.6 to 15.7.2, because in updates it is only showing 16.2, and I finally found your article about how to update from 15.6 to 15.7.2.
First, I downloaded your delay profile and followed your instructions, and I found the iOS 15 beta profile somewhere on another website and installed it.
Second, I went to settings and updates, where I found 15.7.2 and downloaded it.
Thirdly, when I try to instal 15.7.2, it says to check your Internet connection and fails to install.
Fourth, I missed making supervised mode, so I downloaded iBackupPro on Windows and tried to make it, but I couldn’t understand how to make it, so I went to YouTube and saw some videos about how to make supervised mode on the iPhone.
Finally, I made my iPhone supervised, and I went to Updates and installed 15.7.2, which I previously downloaded. It went smoothly, and I skipped entering my Apple ID after installing 15.7.2.
Lastly, I again cleaned the installation by erasing all content and settings. (General settings—transfer or reset iPhone)
Now I entered my Apple ID, and the same as when I first bought my iPhone, it downloaded all my iCloud photos and everything else it synced to iCloud.