I just have to add my +1 to the fact that this migration has been handled extremely poorly. I made an effort to test this as early as possible, and 4 months ago reported discrepancies between the recognized user agents in the legacy prerendering service, and those that the new one recognizes, and my detailed feedback has fallen on deaf ears. Now we find ourselves left with no choice but to experience a serious regression in functionality, or do an expensive migration to a 3rd-party service.