Hi there!
The SyncE support are briefly mentioned in datasheet for LX2 series but unfortunately not much information given on this topic.
The reference manual explains the internals of the PTP1588 support but the SyncE doesn't mentioned there either.
The same thing goes with the evaluation board where recovered clock pins that corresponds to the SyncE are connected to the test points and haven't lead anywhere else.
And there isn't any application note on this topic.
Is there any exapmle of the SyncE implementation?