JWR:
Is there any sort of minimum standard mentioned in the UFB plan?
Minimum? No. Because the only speed that's guaranteed on your UFB is your CIR component. Your headline speed is only an EIR.
There are however specs detailing what sort of throughput should be delivered, with this based on a % based on the number of tests done as fair weighted queuing will be performed with all EIR low priority traffic under congestion conditions. I don't have a link handy but this is will be publically available from Chorus on their site or from CFH.