I contacted BT support who have told me a combination of:
DLM will be removed from my line within 24 hours
When it wasn't, I chased up and the response was:
The exchange monitoring the stability of the line regardless if it's copper or fibre it cannot be removed.
It's hilarious how every time I call BT I get a different answer.
Helpdesk have eventually confirmed what I said in last post DLM cannot be removed