What is the option if the address indicated on the Proof of Address (PoA) document appears to be inadequate for postal delivery? Can additional information from the individual seeking enrolment can be accepted?

Yes. The  individual seeking enrolment is allowed to add minor fields to the address mentioned in the PoA document as long as these additions/modifications do not alter the base address mentioned in the PoA document. If the changes required are substantial and change the base address,  document with correct address to be provided as POA.