I have a mk4 faceplate so i removed the front and used the filter that came with the hub it showed 79.5/20 sync.
obviously this isnt practical so have returned the faceplate
Setup a live BQM to show how stable it is overnight
Ill check in the morning.
and current Smart Hub stats with sync .
In regards to the worry of being charged for an engineer visit I'm not worried i explained the issue in depth to the person who booked the engineer and have checked everything which i have control of (Within my property) and if anything is at fault it will be either the Hub , BT's wiring or some sort of fault at the cabinet/exchange. I have all the evidence at hand of the dropouts and low syncs and speeds so if i don't get a good enough response or fix I intend to walk from the contract as they cannot fulfil their end of the agreement.