iOS 15.2 broke Safari extension preferences storage

from blog The Desolation of Blog, | ↗ original
Apple made a breaking change to Safari extension preferences storage in iOS 15.2 and iPadOS 15.2, which were released to the public yesterday. I believe but haven't confirmed that this breaking change was also made in Safari 15.2 for macOS, which was included in yesterday's Monterey update. I assume that Safari 15.2 is forthcoming for macOS Big Sur and Catalina too, though for some reason it hasn't yet been released (despite the 0day security vulnerabilities already announced in the release notes).