The stats in the attached photo of an installation engineer's JDSU display are the minimum that you should be asking to see.
The supplied modem will be locked, so the best you will be able to obtain data-wise for yourself will be results of BT's speed tests (includes IP Profile data that SHOULD be 96.79% of sync speed).
You may ask Plusnet for ongoing connection data that would show actual sync speed & time between resyncs etc.
That is usually only provided during "fault" investigations though.
The best/cheapest option (stats-wise) is currently to unofficially unlock the HG612 modem or obtain a spare one to unlock.
You would then have access to all the stats you could desire, either as snapshots of the connection or via ongoing logging 24/7.
Other very highly priced combined VDSL2 modem/routers that provide connection stats CAN be used (unofficially).
Hopefully, as you apparently are so close to the cabinet, you will enjoy a high speed & trouble-free connection from day one.
Plusnet may just start you off on a 40/10 connection, updating it to 80/20 after a day or so.
Occasionally, they need a subtle nudge to change to the 80/20 service.