Just updated to Safari 12.0. When I reopened Safari, it said it was removing the AdGuard button because it is slowing things down and has an update. I couldn't find an update anywhere. The button in the lower right corner is still there.
It's back! Thank you. I wish Apple would have just given us a warning and we could make the decision for ourselves rather than automatically cutting it, saying there was a new version (a lie) and not telling us that reactivation was available. That was *not* nice Apple!
There's no reason to use the AG browser extension in Safari if you're already using the AG for Mac app. Mostly because Safari still doesn't support what's needed to get integration mode working (where you can use the AG browser extension as a replacement for the AG Assistant in AG for Win/Mac) and using both at the same time would be counterproductive.