In a construction contract, does the concept of 'beneficial occupation' have any merit, and is an architect legally obliged to certify practical completion at the time that an employer takes possession of the Works?

There are some standard form contracts that permit ‘beneficial occupation’, one such example is JCT Standard Building Contract 2009 clause 2.6. This occupation in no way influences the contractor’s exclusive possession of the Works, nor does it absolve the contractor of responsibility with regards to liquidated damages.