As implied by the order confirmation, waited in all day to ensure that the 'eqipment' was on site for the engineer's visit.
When it didn't arrive (and no information via the delivery 'Tracking' link provided) followed up by phone.
"No problem - the engineer will have spare equipment with them"
Having wasted a day - not amused, and mentioned it to the Openreach engineer when he arrived.
Apparently it is due to the 'Chinese Walls' between BT and Openreach - they can't be seen to be providing a preferential service to BT by carrying stocks of their modems!
Surely Openreach could get around this by offering a similar consignment stock service for all ISPs? It would remove one potential point of failure in the installation process - not to mention saving customers wasting a day waiting in for a courrier delivery (whether it turns up or not!).
On reflection, it was probably the new 'BT HomeHub4' that was being delivered separately (ISTR the modem was branded OpenReach).
But what is the logic of not carrying stock of the new router?
Even if they charge BT (and other ISPs - can't be that many of them?) the same cost as having the router sent separately by courier, it would avoid customers having to be at home all day on two occasions - and would also obviate the re-scheduling of engineer appointments on the inevitable occasions when the parts fail to arrive.