If you have not already done so, I suggest that you do Quiet Line Tests on your Phone Line, to ensure that it is in a good state for the upgrade, particularly the PCP Cabinet to House length; and of course within the house.
Also try to establish the line length from your PCP to your house more accurately, using the BRAS Test-
As regards that distance, my PCP is about 50 Metres from my house; BUT about 250 Metres by its known physical routing.
The associated FTTC Cabinet is about 15 M from my house; BUT is linked to the PCP by about 50 Metres from the PCP, thus in total, my VDSL routing has increased to about 300 Metres!
The 250 Metres because the original phone wiring heads about 125 M Eastwards along the street, to a known small surface junction box, then back to my house.
The estate was one of the first to be fully wired for phones, back in 1967.
Even the 2014-installed FTTC cabinet has a quirk - the links to the PCP double back towards the Exchange, beside the fibre, before heading towards the old PCP cabinet, thus adding about 15 M of otherwise unnecessary wiring.
And the FTTC would have been more readily installed beside the PCP, there being plenty of room, power supplies, recessed etc; yet is actually situated where it partially obscures a road junction, at a school double crossing!