Regular PTP is old hat as you say. ~5ns though I thought needs some real thought, and picosecond sync needs a combo of PTP + SyncE + link compensation, which is

Regular PTP is old hat as you say. ~5ns though I thought needs some real thought, and picosecond sync needs a combo of PTP + SyncE + link compensation, which is now the "high accuracy" profile. It's all fairly simple in the end if the hw has the tools but good luck buying SyncE or 1588 without $$$.